78 lines
2.3 KiB
Plaintext
78 lines
2.3 KiB
Plaintext
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Commands_all.html)
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:line
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angle_style harmonic command :h3
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angle_style harmonic/intel command :h3
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angle_style harmonic/kk command :h3
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angle_style harmonic/omp command :h3
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[Syntax:]
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angle_style harmonic :pre
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[Examples:]
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angle_style harmonic
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angle_coeff 1 300.0 107.0 :pre
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[Description:]
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The {harmonic} angle style uses the potential
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:c,image(Eqs/angle_harmonic.jpg)
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where theta0 is the equilibrium value of the angle, and K is a
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prefactor. Note that the usual 1/2 factor is included in K.
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The following coefficients must be defined for each angle type via the
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"angle_coeff"_angle_coeff.html command as in the example above, or in
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the data file or restart files read by the "read_data"_read_data.html
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or "read_restart"_read_restart.html commands:
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K (energy/radian^2)
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theta0 (degrees) :ul
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Theta0 is specified in degrees, but LAMMPS converts it to radians
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internally; hence the units of K are in energy/radian^2.
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:line
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Styles with a {gpu}, {intel}, {kk}, {omp}, or {opt} suffix are
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functionally the same as the corresponding style without the suffix.
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They have been optimized to run faster, depending on your available
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hardware, as discussed on the "Speed packages"_Speed_packages.html doc
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page. The accelerated styles take the same arguments and should
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produce the same results, except for round-off and precision issues.
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These accelerated styles are part of the GPU, USER-INTEL, KOKKOS,
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USER-OMP and OPT packages, respectively. They are only enabled if
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LAMMPS was built with those packages. See the "Build
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package"_Build_package.html doc page for more info.
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You can specify the accelerated styles explicitly in your input script
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by including their suffix, or you can use the "-suffix command-line
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switch"_Run_options.html when you invoke LAMMPS, or you can use the
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"suffix"_suffix.html command in your input script.
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See the "Speed packages"_Speed_packages.html doc page for more
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instructions on how to use the accelerated styles effectively.
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:line
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[Restrictions:]
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This angle style can only be used if LAMMPS was built with the
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MOLECULE package. See the "Build package"_Build_package.html doc
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page for more info.
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[Related commands:]
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"angle_coeff"_angle_coeff.html
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[Default:] none
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