583 lines
51 KiB
HTML
583 lines
51 KiB
HTML
<!DOCTYPE html>
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<html class="writer-html5" lang="en" >
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<title>fix addforce command — LAMMPS documentation</title>
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<link rel="index" title="Index" href="genindex.html" />
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<link rel="search" title="Search" href="search.html" />
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<link rel="next" title="fix addtorque command" href="fix_addtorque.html" />
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<img src="_static/lammps-logo.png" class="logo" alt="Logo"/>
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<div class="lammps_version">Version: <b>19 Nov 2024</b></div>
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</div><div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu">
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<p class="caption" role="heading"><span class="caption-text">User Guide</span></p>
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<ul>
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<li class="toctree-l1"><a class="reference internal" href="Intro.html">1. Introduction</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Install.html">2. Install LAMMPS</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Build.html">3. Build LAMMPS</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Run_head.html">4. Run LAMMPS</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Commands.html">5. Commands</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Packages.html">6. Optional packages</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Speed.html">7. Accelerate performance</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Howto.html">8. Howto discussions</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Examples.html">9. Example scripts</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Tools.html">10. Auxiliary tools</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Errors.html">11. Errors</a></li>
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<p class="caption" role="heading"><span class="caption-text">Programmer Guide</span></p>
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<ul>
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<li class="toctree-l1"><a class="reference internal" href="Library.html">1. LAMMPS Library Interfaces</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Python_head.html">2. Use Python with LAMMPS</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Modify.html">3. Modifying & extending LAMMPS</a></li>
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<li class="toctree-l1"><a class="reference internal" href="Developer.html">4. Information for Developers</a></li>
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</ul>
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<p class="caption" role="heading"><span class="caption-text">Command Reference</span></p>
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<ul class="current">
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<li class="toctree-l1"><a class="reference internal" href="commands_list.html">Commands</a></li>
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<li class="toctree-l1 current"><a class="reference internal" href="fixes.html">Fix Styles</a><ul class="current">
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<li class="toctree-l2"><a class="reference internal" href="fix_accelerate_cos.html">fix accelerate/cos command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_acks2_reaxff.html">fix acks2/reaxff command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_adapt.html">fix adapt command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_adapt_fep.html">fix adapt/fep command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_add_heat.html">fix add/heat command</a></li>
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<li class="toctree-l2 current"><a class="current reference internal" href="#">fix addforce command</a><ul>
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<li class="toctree-l3"><a class="reference internal" href="#syntax">Syntax</a></li>
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<li class="toctree-l3"><a class="reference internal" href="#examples">Examples</a></li>
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<li class="toctree-l3"><a class="reference internal" href="#description">Description</a></li>
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<li class="toctree-l3"><a class="reference internal" href="#restart-fix-modify-output-run-start-stop-minimize-info">Restart, fix_modify, output, run start/stop, minimize info</a></li>
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<li class="toctree-l3"><a class="reference internal" href="#restrictions">Restrictions</a></li>
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<li class="toctree-l3"><a class="reference internal" href="#related-commands">Related commands</a></li>
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<li class="toctree-l3"><a class="reference internal" href="#default">Default</a></li>
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</ul>
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</li>
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<li class="toctree-l2"><a class="reference internal" href="fix_addtorque.html">fix addtorque command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_alchemy.html">fix alchemy command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_amoeba_bitorsion.html">fix amoeba/bitorsion command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_amoeba_pitorsion.html">fix amoeba/pitorsion command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_append_atoms.html">fix append/atoms command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_atc.html">fix atc command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_atom_swap.html">fix atom/swap command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_atom.html">fix ave/atom command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_chunk.html">fix ave/chunk command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_correlate.html">fix ave/correlate command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_correlate_long.html">fix ave/correlate/long command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_grid.html">fix ave/grid command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_histo.html">fix ave/histo command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_histo.html#fix-ave-histo-weight-command">fix ave/histo/weight command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_spatial.html">fix ave/spatial command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_spatial_sphere.html">fix ave/spatial/sphere command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ave_time.html">fix ave/time command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_aveforce.html">fix aveforce command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_balance.html">fix balance command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_bocs.html">fix bocs command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_bond_break.html">fix bond/break command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_bond_create.html">fix bond/create command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_bond_create.html#fix-bond-create-angle-command">fix bond/create/angle command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_bond_react.html">fix bond/react command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_bond_swap.html">fix bond/swap command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_box_relax.html">fix box/relax command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_brownian.html">fix brownian command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_brownian.html#fix-brownian-sphere-command">fix brownian/sphere command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_brownian.html#fix-brownian-asphere-command">fix brownian/asphere command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_charge_regulation.html">fix charge/regulation command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_cmap.html">fix cmap command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_colvars.html">fix colvars command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_controller.html">fix controller command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_damping_cundall.html">fix damping/cundall command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_deform.html">fix deform command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_deform_pressure.html">fix deform/pressure command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_deposit.html">fix deposit command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_dpd_energy.html">fix dpd/energy command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_dpd_source.html">fix edpd/source command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_dpd_source.html#fix-tdpd-source-command">fix tdpd/source command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_drag.html">fix drag command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_drude.html">fix drude command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_drude_transform.html">fix drude/transform/direct command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_drude_transform.html#fix-drude-transform-inverse-command">fix drude/transform/inverse command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_dt_reset.html">fix dt/reset command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_efield.html">fix efield command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_efield.html#fix-efield-tip4p-command">fix efield/tip4p command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ehex.html">fix ehex command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_electrode.html">fix electrode/conp command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_electrode.html#fix-electrode-conq-command">fix electrode/conq command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_electrode.html#fix-electrode-thermo-command">fix electrode/thermo command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_electron_stopping.html">fix electron/stopping command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_electron_stopping.html#fix-electron-stopping-fit-command">fix electron/stopping/fit command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_enforce2d.html">fix enforce2d command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_eos_cv.html">fix eos/cv command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_eos_table.html">fix eos/table command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_eos_table_rx.html">fix eos/table/rx command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_evaporate.html">fix evaporate command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_external.html">fix external command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ffl.html">fix ffl command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_filter_corotate.html">fix filter/corotate command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_flow_gauss.html">fix flow/gauss command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_freeze.html">fix freeze command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_gcmc.html">fix gcmc command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_gld.html">fix gld command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_gle.html">fix gle command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_gravity.html">fix gravity command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_grem.html">fix grem command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_halt.html">fix halt command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_heat.html">fix heat command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_heat_flow.html">fix heat/flow command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_hyper_global.html">fix hyper/global command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_hyper_local.html">fix hyper/local command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_imd.html">fix imd command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_indent.html">fix indent command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_ipi.html">fix ipi command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_langevin.html">fix langevin command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_langevin_drude.html">fix langevin/drude command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_langevin_eff.html">fix langevin/eff command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_langevin_spin.html">fix langevin/spin command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_lb_fluid.html">fix lb/fluid command</a></li>
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<li class="toctree-l2"><a class="reference internal" href="fix_lb_momentum.html">fix lb/momentum command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_lb_viscous.html">fix lb/viscous command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_lineforce.html">fix lineforce command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_manifoldforce.html">fix manifoldforce command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_mdi_qm.html">fix mdi/qm command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_mdi_qmmm.html">fix mdi/qmmm command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_meso_move.html">fix meso/move command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_mol_swap.html">fix mol/swap command</a></li>
|
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<li class="toctree-l2"><a class="reference internal" href="fix_momentum.html">fix momentum command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_momentum.html#fix-momentum-chunk-command">fix momentum/chunk command</a></li>
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||
<li class="toctree-l2"><a class="reference internal" href="fix_move.html">fix move command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_msst.html">fix msst command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_mvv_dpd.html">fix mvv/dpd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_mvv_dpd.html#fix-mvv-edpd-command">fix mvv/edpd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_mvv_dpd.html#fix-mvv-tdpd-command">fix mvv/tdpd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_neb.html">fix neb command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_neb_spin.html">fix neb/spin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh.html">fix nvt command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-npt-command">fix npt command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh.html#fix-nph-command">fix nph command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh_eff.html">fix nvt/eff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh_eff.html#fix-npt-eff-command">fix npt/eff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh_eff.html#fix-nph-eff-command">fix nph/eff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh_uef.html">fix nvt/uef command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nh_uef.html#fix-npt-uef-command">fix npt/uef command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nonaffine_displacement.html">fix nonaffine/displacement command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nph_asphere.html">fix nph/asphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nph_body.html">fix nph/body command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nph_sphere.html">fix nph/sphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nphug.html">fix nphug command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_npt_asphere.html">fix npt/asphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_npt_body.html">fix npt/body command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_npt_cauchy.html">fix npt/cauchy command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_npt_sphere.html">fix npt/sphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_numdiff.html">fix numdiff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_numdiff_virial.html">fix numdiff/virial command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve.html">fix nve command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_asphere.html">fix nve/asphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_asphere_noforce.html">fix nve/asphere/noforce command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_awpmd.html">fix nve/awpmd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_body.html">fix nve/body command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_bpm_sphere.html">fix nve/bpm/sphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_dot.html">fix nve/dot command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_dotc_langevin.html">fix nve/dotc/langevin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_eff.html">fix nve/eff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_limit.html">fix nve/limit command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_line.html">fix nve/line command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_manifold_rattle.html">fix nve/manifold/rattle command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_noforce.html">fix nve/noforce command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_sphere.html">fix nve/sphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_spin.html">fix nve/spin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nve_tri.html">fix nve/tri command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nvk.html">fix nvk command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nvt_asphere.html">fix nvt/asphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nvt_body.html">fix nvt/body command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nvt_manifold_rattle.html">fix nvt/manifold/rattle command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sllod.html">fix nvt/sllod command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sllod_eff.html">fix nvt/sllod/eff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_nvt_sphere.html">fix nvt/sphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_oneway.html">fix oneway command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_orient.html">fix orient/fcc command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_orient.html#fix-orient-bcc-command">fix orient/bcc command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_orient_eco.html">fix orient/eco command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_pafi.html">fix pafi command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_pair.html">fix pair command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_phonon.html">fix phonon command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_pimd.html">fix pimd/langevin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_pimd.html#fix-pimd-nvt-command">fix pimd/nvt command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_pimdb.html">fix pimdb/langevin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_pimdb.html#fix-pimdb-nvt-command">fix pimdb/nvt command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_planeforce.html">fix planeforce command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_plumed.html">fix plumed command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_poems.html">fix poems command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_polarize.html">fix polarize/bem/gmres command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_polarize.html#fix-polarize-bem-icc-command">fix polarize/bem/icc command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_polarize.html#fix-polarize-functional-command">fix polarize/functional command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_pour.html">fix pour command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_precession_spin.html">fix precession/spin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_press_berendsen.html">fix press/berendsen command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_press_langevin.html">fix press/langevin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_print.html">fix print command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_propel_self.html">fix propel/self command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_property_atom.html">fix property/atom command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_python_invoke.html">fix python/invoke command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_python_move.html">fix python/move command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qbmsst.html">fix qbmsst command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html">fix qeq/point command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-shielded-command">fix qeq/shielded command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-slater-command">fix qeq/slater command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-ctip-command">fix qeq/ctip command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-dynamic-command">fix qeq/dynamic command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq.html#fix-qeq-fire-command">fix qeq/fire command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq_comb.html">fix qeq/comb command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qeq_reaxff.html">fix qeq/reaxff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qmmm.html">fix qmmm command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qtb.html">fix qtb command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_qtpie_reaxff.html">fix qtpie/reaxff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_reaxff_bonds.html">fix reaxff/bonds command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_reaxff_species.html">fix reaxff/species command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_recenter.html">fix recenter command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_restrain.html">fix restrain command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rheo.html">fix rheo command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rheo_oxidation.html">fix rheo/oxidation command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rheo_pressure.html">fix rheo/pressure command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rheo_thermal.html">fix rheo/thermal command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rheo_viscosity.html">fix rheo/viscosity command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rhok.html">fix rhok command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html">fix rigid command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-nve-command">fix rigid/nve command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-nvt-command">fix rigid/nvt command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-npt-command">fix rigid/npt command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-nph-command">fix rigid/nph command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-small-command">fix rigid/small command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-nve-small-command">fix rigid/nve/small command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-nvt-small-command">fix rigid/nvt/small command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-npt-small-command">fix rigid/npt/small command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid.html#fix-rigid-nph-small-command">fix rigid/nph/small command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rigid_meso.html">fix rigid/meso command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_rx.html">fix rx command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_saed_vtk.html">fix saed/vtk command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_setforce.html">fix setforce command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_setforce.html#fix-setforce-spin-command">fix setforce/spin command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_sgcmc.html">fix sgcmc command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_shake.html">fix shake command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_shake.html#fix-rattle-command">fix rattle command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_shardlow.html">fix shardlow command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_smd.html">fix smd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_smd_adjust_dt.html">fix smd/adjust_dt command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_smd_integrate_tlsph.html">fix smd/integrate_tlsph command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_smd_integrate_ulsph.html">fix smd/integrate_ulsph command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_smd_move_triangulated_surface.html">fix smd/move_tri_surf command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_smd_setvel.html">fix smd/setvel command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_smd_wall_surface.html">fix smd/wall_surface command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_sph.html">fix sph command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_sph_stationary.html">fix sph/stationary command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_spring.html">fix spring command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_spring_chunk.html">fix spring/chunk command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_spring_rg.html">fix spring/rg command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_spring_self.html">fix spring/self command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_srd.html">fix srd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_store_force.html">fix store/force command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_store_state.html">fix store/state command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_temp_berendsen.html">fix temp/berendsen command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_temp_csvr.html">fix temp/csvr command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_temp_csvr.html#fix-temp-csld-command">fix temp/csld command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_temp_rescale.html">fix temp/rescale command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_temp_rescale_eff.html">fix temp/rescale/eff command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_tfmc.html">fix tfmc command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_tgnh_drude.html">fix tgnvt/drude command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_tgnh_drude.html#fix-tgnpt-drude-command">fix tgnpt/drude command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_thermal_conductivity.html">fix thermal/conductivity command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_ti_spring.html">fix ti/spring command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_tmd.html">fix tmd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_ttm.html">fix ttm command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_ttm.html#fix-ttm-grid-command">fix ttm/grid command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_ttm.html#fix-ttm-mod-command">fix ttm/mod command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_tune_kspace.html">fix tune/kspace command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_vector.html">fix vector command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_viscosity.html">fix viscosity command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_viscous.html">fix viscous command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_viscous_sphere.html">fix viscous/sphere command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html">fix wall/lj93 command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-lj126-command">fix wall/lj126 command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-lj1043-command">fix wall/lj1043 command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-colloid-command">fix wall/colloid command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-harmonic-command">fix wall/harmonic command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-lepton-command">fix wall/lepton command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-morse-command">fix wall/morse command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall.html#fix-wall-table-command">fix wall/table command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_body_polygon.html">fix wall/body/polygon command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_body_polyhedron.html">fix wall/body/polyhedron command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_ees.html">fix wall/ees command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_ees.html#fix-wall-region-ees-command">fix wall/region/ees command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_flow.html">fix wall/flow command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_gran.html">fix wall/gran command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_gran_region.html">fix wall/gran/region command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_piston.html">fix wall/piston command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_reflect.html">fix wall/reflect command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_reflect_stochastic.html">fix wall/reflect/stochastic command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_region.html">fix wall/region command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_wall_srd.html">fix wall/srd command</a></li>
|
||
<li class="toctree-l2"><a class="reference internal" href="fix_widom.html">fix widom command</a></li>
|
||
</ul>
|
||
</li>
|
||
<li class="toctree-l1"><a class="reference internal" href="computes.html">Compute Styles</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="pairs.html">Pair Styles</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="bonds.html">Bond Styles</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="angles.html">Angle Styles</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="dihedrals.html">Dihedral Styles</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="impropers.html">Improper Styles</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="dumps.html">Dump Styles</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="fix_modify_atc_commands.html">fix_modify AtC commands</a></li>
|
||
<li class="toctree-l1"><a class="reference internal" href="Bibliography.html">Bibliography</a></li>
|
||
</ul>
|
||
|
||
</div>
|
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</div>
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<li><a href="Manual.html" class="icon icon-home" aria-label="Home"></a></li>
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<li class="breadcrumb-item"><a href="fixes.html">Fix Styles</a></li>
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<li class="breadcrumb-item active">fix addforce command</li>
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</ul><div class="rst-breadcrumbs-buttons" role="navigation" aria-label="Sequential page navigation">
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<a href="fix_addtorque.html" class="btn btn-neutral float-right" title="fix addtorque command" accesskey="n">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a>
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<div itemprop="articleBody">
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|
||
<p><span class="math notranslate nohighlight">\(\renewcommand{\AA}{\text{Å}}\)</span></p>
|
||
<section id="fix-addforce-command">
|
||
<span id="index-0"></span><h1>fix addforce command<a class="headerlink" href="#fix-addforce-command" title="Link to this heading"></a></h1>
|
||
<section id="syntax">
|
||
<h2>Syntax<a class="headerlink" href="#syntax" title="Link to this heading"></a></h2>
|
||
<div class="highlight-LAMMPS notranslate"><div class="highlight"><pre><span></span><span class="k">fix </span><span class="nv nv-Identifier">ID</span><span class="w"> </span><span class="nv nv-Identifier">group-ID</span><span class="w"> </span><span class="n">addforce</span><span class="w"> </span><span class="n">fx</span><span class="w"> </span><span class="n">fy</span><span class="w"> </span><span class="n">fz</span><span class="w"> </span><span class="n">keyword</span><span class="w"> </span><span class="n">value</span><span class="w"> </span><span class="n">...</span>
|
||
</pre></div>
|
||
</div>
|
||
<ul>
|
||
<li><p>ID, group-ID are documented in <a class="reference internal" href="fix.html"><span class="doc">fix</span></a> command</p></li>
|
||
<li><p>addforce = style name of this fix command</p></li>
|
||
<li><p>fx,fy,fz = force component values (force units)</p>
|
||
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>any of fx,fy,fz can be a variable (see below)
|
||
</pre></div>
|
||
</div>
|
||
</li>
|
||
<li><p>zero or more keyword/value pairs may be appended to args</p></li>
|
||
<li><p>keyword = <em>every</em> or <em>region</em> or <em>energy</em></p>
|
||
<pre class="literal-block"><em>every</em> value = Nevery
|
||
Nevery = add force every this many time steps
|
||
<em>region</em> value = region-ID
|
||
region-ID = ID of region atoms must be in to have added force
|
||
<em>energy</em> value = v_name
|
||
v_name = variable with name that calculates the potential energy of each atom in the added force field</pre>
|
||
</li>
|
||
</ul>
|
||
</section>
|
||
<section id="examples">
|
||
<h2>Examples<a class="headerlink" href="#examples" title="Link to this heading"></a></h2>
|
||
<div class="highlight-LAMMPS notranslate"><div class="highlight"><pre><span></span><span class="k">fix </span><span class="nv nv-Identifier">kick</span><span class="w"> </span><span class="nv nv-Identifier">flow</span><span class="w"> </span><span class="n">addforce</span><span class="w"> </span><span class="m">1.0</span><span class="w"> </span><span class="m">0.0</span><span class="w"> </span><span class="m">0.0</span>
|
||
<span class="k">fix </span><span class="nv nv-Identifier">kick</span><span class="w"> </span><span class="nv nv-Identifier">flow</span><span class="w"> </span><span class="n">addforce</span><span class="w"> </span><span class="m">1.0</span><span class="w"> </span><span class="m">0.0</span><span class="w"> </span><span class="n">v_oscillate</span>
|
||
<span class="k">fix </span><span class="nv nv-Identifier">ff</span><span class="w"> </span><span class="nv nv-Identifier">boundary</span><span class="w"> </span><span class="n">addforce</span><span class="w"> </span><span class="m">0.0</span><span class="w"> </span><span class="m">0.0</span><span class="w"> </span><span class="n">v_push</span><span class="w"> </span><span class="n">energy</span><span class="w"> </span><span class="n">v_espace</span>
|
||
</pre></div>
|
||
</div>
|
||
</section>
|
||
<section id="description">
|
||
<h2>Description<a class="headerlink" href="#description" title="Link to this heading"></a></h2>
|
||
<p>Add <span class="math notranslate nohighlight">\((f_x,f_y,f_z)\)</span> to the corresponding component of the force for each
|
||
atom in the group. This command can be used to give an additional push to
|
||
atoms in a simulation, such as for a simulation of Poiseuille flow in
|
||
a channel.</p>
|
||
<p>Any of the three quantities defining the force components, namely <span class="math notranslate nohighlight">\(f_x\)</span>,
|
||
<span class="math notranslate nohighlight">\(f_y\)</span>, and <span class="math notranslate nohighlight">\(f_z\)</span>, can be specified as an equal-style or atom-style
|
||
<a class="reference internal" href="variable.html"><span class="doc">variable</span></a>. If the value is a variable, it should be specified
|
||
as v_name, where name is the variable name. In this case, the variable
|
||
will be evaluated each time step, and its value(s) will be used to determine
|
||
the force component(s).</p>
|
||
<p>Equal-style variables can specify formulas with various mathematical
|
||
functions and include <a class="reference internal" href="thermo_style.html"><span class="doc">thermo_style</span></a> command
|
||
keywords for the simulation box parameters, time step, and elapsed time.
|
||
Thus, it is easy to specify a time-dependent force field.</p>
|
||
<p>Atom-style variables can specify the same formulas as equal-style
|
||
variables but can also include per-atom values, such as atom
|
||
coordinates. Thus, it is easy to specify a spatially-dependent force
|
||
field with optional time-dependence as well.</p>
|
||
<p>If the <em>every</em> keyword is used, the <em>Nevery</em> setting determines how
|
||
often the forces are applied. The default value is 1, for every
|
||
time step.</p>
|
||
<p>If the <em>region</em> keyword is used, the atom must also be in the
|
||
specified geometric <a class="reference internal" href="region.html"><span class="doc">region</span></a> in order to have force added
|
||
to it.</p>
|
||
<hr class="docutils" />
|
||
<p>Adding a force to atoms implies a change in their potential energy as
|
||
they move due to the applied force field. For dynamics via the “run”
|
||
command, this energy can be optionally added to the system’s potential
|
||
energy for thermodynamic output (see below). For energy minimization
|
||
via the “minimize” command, this energy must be added to the system’s
|
||
potential energy to formulate a self-consistent minimization problem
|
||
(see below).</p>
|
||
<p>The <em>energy</em> keyword is not allowed if the added force is a constant
|
||
vector <span class="math notranslate nohighlight">\(\vec F = (f_x,f_y,f_z)\)</span>, with all components defined as numeric
|
||
constants and not as variables. This is because LAMMPS can compute
|
||
the energy for each atom directly as</p>
|
||
<div class="math notranslate nohighlight">
|
||
\[E = -\vec x \cdot \vec F = -(x f_x + y f_y + z f_z),\]</div>
|
||
<p>so that <span class="math notranslate nohighlight">\(-\vec\nabla E = \vec F\)</span>.</p>
|
||
<p>The <em>energy</em> keyword is optional if the added force is defined with
|
||
one or more variables, and if you are performing dynamics via the
|
||
<a class="reference internal" href="run.html"><span class="doc">run</span></a> command. If the keyword is not used, LAMMPS will set
|
||
the energy to 0.0, which is typically fine for dynamics.</p>
|
||
<p>The <em>energy</em> keyword is required if the added force is defined with
|
||
one or more variables, and you are performing energy minimization via
|
||
the “minimize” command. The keyword specifies the name of an
|
||
atom-style <a class="reference internal" href="variable.html"><span class="doc">variable</span></a> which is used to compute the
|
||
energy of each atom as function of its position. Like variables used
|
||
for <span class="math notranslate nohighlight">\(f_x\)</span>, <span class="math notranslate nohighlight">\(f_y\)</span>, <span class="math notranslate nohighlight">\(f_z\)</span>, the energy variable is specified as
|
||
v_name, where name is the variable name.</p>
|
||
<p>Note that when the <em>energy</em> keyword is used during an energy
|
||
minimization, you must ensure that the formula defined for the
|
||
atom-style <a class="reference internal" href="variable.html"><span class="doc">variable</span></a> is consistent with the force
|
||
variable formulas (i.e., that <span class="math notranslate nohighlight">\(-\vec\nabla E = \vec F\)</span>).
|
||
For example, if the force were a spring-like, <span class="math notranslate nohighlight">\(\vec F = -k\vec x\)</span>, then
|
||
the energy formula should be <span class="math notranslate nohighlight">\(E = \frac12 kx^2\)</span>. If you do not do this
|
||
correctly, the minimization will not converge properly.</p>
|
||
</section>
|
||
<hr class="docutils" />
|
||
<section id="restart-fix-modify-output-run-start-stop-minimize-info">
|
||
<h2>Restart, fix_modify, output, run start/stop, minimize info<a class="headerlink" href="#restart-fix-modify-output-run-start-stop-minimize-info" title="Link to this heading"></a></h2>
|
||
<p>No information about this fix is written to <a class="reference internal" href="restart.html"><span class="doc">binary restart files</span></a>.</p>
|
||
<p>The <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify</span></a> <em>energy</em> option is supported by
|
||
this fix to add the potential energy inferred by the added force to
|
||
the global potential energy of the system as part of
|
||
<a class="reference internal" href="thermo_style.html"><span class="doc">thermodynamic output</span></a>. The default setting for
|
||
this fix is <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify energy no</span></a>. Note that this
|
||
energy is a fictitious quantity but is needed so that the
|
||
<a class="reference internal" href="minimize.html"><span class="doc">minimize</span></a> command can include the forces added by
|
||
this fix in a consistent manner (i.e., there is a decrease in
|
||
potential energy when atoms move in the direction of the added force).</p>
|
||
<p>The <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify</span></a> <em>virial</em> option is supported by
|
||
this fix to add the contribution due to the added forces on atoms to
|
||
both the global pressure and per-atom stress of the system via the
|
||
<a class="reference internal" href="compute_pressure.html"><span class="doc">compute pressure</span></a> and <a class="reference internal" href="compute_stress_atom.html"><span class="doc">compute
|
||
stress/atom</span></a> commands. The former can be
|
||
accessed by <a class="reference internal" href="thermo_style.html"><span class="doc">thermodynamic output</span></a>. The default
|
||
setting for this fix is <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify virial no</span></a>.</p>
|
||
<p>The <a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify</span></a> <em>respa</em> option is supported by this
|
||
fix. This allows to set at which level of the <a class="reference internal" href="run_style.html"><span class="doc">r-RESPA</span></a> integrator the fix is adding its forces. Default is the
|
||
outermost level.</p>
|
||
<p>This fix computes a global scalar and a global three-vector of forces,
|
||
which can be accessed by various <a class="reference internal" href="Howto_output.html"><span class="doc">output commands</span></a>. The scalar is the potential energy discussed above.
|
||
The vector is the total force on the group of atoms before the forces
|
||
on individual atoms are changed by the fix. The scalar and vector
|
||
values calculated by this fix are “extensive”.</p>
|
||
<p>No parameter of this fix can be used with the <em>start/stop</em> keywords of
|
||
the <a class="reference internal" href="run.html"><span class="doc">run</span></a> command.</p>
|
||
<p>The forces due to this fix are imposed during an energy minimization,
|
||
invoked by the <a class="reference internal" href="minimize.html"><span class="doc">minimize</span></a> command. You should not
|
||
specify force components with a variable that has time-dependence for
|
||
use with a minimizer, since the minimizer increments the time step as
|
||
the iteration count during the minimization.</p>
|
||
<div class="admonition note">
|
||
<p class="admonition-title">Note</p>
|
||
<p>If you want the fictitious potential energy associated with the
|
||
added forces to be included in the total potential energy of the
|
||
system (the quantity being minimized), you MUST enable the
|
||
<a class="reference internal" href="fix_modify.html"><span class="doc">fix_modify</span></a> <em>energy</em> option for this fix.</p>
|
||
</div>
|
||
</section>
|
||
<section id="restrictions">
|
||
<h2>Restrictions<a class="headerlink" href="#restrictions" title="Link to this heading"></a></h2>
|
||
<blockquote>
|
||
<div><p>none</p>
|
||
</div></blockquote>
|
||
</section>
|
||
<section id="related-commands">
|
||
<h2>Related commands<a class="headerlink" href="#related-commands" title="Link to this heading"></a></h2>
|
||
<p><a class="reference internal" href="fix_setforce.html"><span class="doc">fix setforce</span></a>, <a class="reference internal" href="fix_aveforce.html"><span class="doc">fix aveforce</span></a></p>
|
||
</section>
|
||
<section id="default">
|
||
<h2>Default<a class="headerlink" href="#default" title="Link to this heading"></a></h2>
|
||
<p>The option default for the every keyword is every = 1.</p>
|
||
</section>
|
||
</section>
|
||
|
||
|
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