Merge pull request #310 from EfremBraun/master

Fix nvk implemented

doc/src/Section_commands.txt

@@ -702,6 +702,7 @@ package"_Section_start.html#start_3.
 "manifoldforce"_fix_manifoldforce.html,
 "meso/stationary"_fix_meso_stationary.html,
 "nve/manifold/rattle"_fix_nve_manifold_rattle.html,
+"nvk"_fix_nvk.html,
 "nvt/manifold/rattle"_fix_nvt_manifold_rattle.html,
 "nph/eff"_fix_nh_eff.html,
 "npt/eff"_fix_nh_eff.html,

doc/src/fix_nvk.txt

@@ -0,0 +1,71 @@
+"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
+
+:link(lws,http://lammps.sandia.gov)
+:link(ld,Manual.html)
+:link(lc,Section_commands.html#comm)
+
+:line
+
+fix nvk command :h3
+
+[Syntax:]
+
+fix ID group-ID nvk :pre
+
+ID, group-ID are documented in "fix"_fix.html command
+nvk = style name of this fix command :ul
+
+[Examples:]
+
+fix 1 all nvk :pre
+
+[Description:]
+
+Perform constant kinetic energy integration using the Gaussian
+thermostat to update position and velocity for atoms in the group each
+timestep.  V is volume; K is kinetic energy. This creates a system
+trajectory consistent with the isokinetic ensemble.
+
+The equations of motion used are those of Minary et al in
+"(Minary)"_#nvk-Minary, a variant of those initially given by Zhang in 
+"(Zhang)"_#nvk-Zhang.
+
+The kinetic energy will be held constant at its value given when fix
+nvk is initiated. If a different kinetic energy is desired, the
+"velocity"_velocity.html command should be used to change the kinetic
+energy prior to this fix.
+
+:line
+
+[Restart, fix_modify, output, run start/stop, minimize info:]
+
+No information about this fix is written to "binary restart
+files"_restart.html.  None of the "fix_modify"_fix_modify.html options
+are relevant to this fix.  No global or per-atom quantities are stored
+by this fix for access by various "output
+commands"_Section_howto.html#howto_15.  No parameter of this fix can
+be used with the {start/stop} keywords of the "run"_run.html command.
+This fix is not invoked during "energy minimization"_minimize.html.
+
+[Restrictions:]
+
+The Gaussian thermostat only works when it is applied to all atoms in
+the simulation box. Therefore, the group must be set to all.
+
+This fix has not yet been implemented to work with the RESPA integrator.
+
+This fix is part of the USER-MISC package.  It is only enabled if LAMMPS
+was built with that package.  See the "Making
+LAMMPS"_Section_start.html#start_3 section for more info.
+
+[Related commands:] none
+
+[Default:] none
+
+:line
+
+:link(nvk-Minary)
+[(Minary)] Minary, Martyna, and Tuckerman, J Chem Phys, 18, 2510 (2003).
+
+:link(nvk-Zhang)
+[(Zhang)] Zhang, J Chem Phys, 106, 6102 (1997).

doc/src/fixes.txt

@@ -90,6 +90,7 @@ Fixes :h1
    fix_nve_noforce
    fix_nve_sphere
    fix_nve_tri
+   fix_nvk
    fix_nvt_asphere
    fix_nvt_body
    fix_nvt_manifold_rattle