forked from lijiext/lammps
98 lines
3.4 KiB
Plaintext
98 lines
3.4 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,Section_commands.html#comm)
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:line
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angle_style command :h3
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[Syntax:]
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angle_style style :pre
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style = {none} or {hybrid} or {charmm} or {class2} or {cosine} or \
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{cosine/squared} or {harmonic} :ul
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[Examples:]
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angle_style harmonic
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angle_style charmm
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angle_style hybrid harmonic cosine :pre
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[Description:]
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Set the formula(s) LAMMPS uses to compute angle interactions between
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triplets of atoms, which remain in force for the duration of the
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simulation. The list of angle triplets is read in by a
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"read_data"_read_data.html or "read_restart"_read_restart.html command
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from a data or restart file.
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Hybrid models where angles are computed using different angle
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potentials can be setup using the {hybrid} angle style.
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The coefficients associated with a angle style can be specified in a
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data or restart file or via the "angle_coeff"_angle_coeff.html command.
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All angle potentials store their coefficient data in binary restart
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files which means angle_style and "angle_coeff"_angle_coeff.html
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commands do not need to be re-specified in an input script that
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restarts a simulation. See the "read_restart"_read_restart.html
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command for details on how to do this. The one exception is that
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angle_style {hybrid} only stores the list of sub-styles in the restart
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file; angle coefficients need to be re-specified.
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NOTE: When both an angle and pair style is defined, the
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"special_bonds"_special_bonds.html command often needs to be used to
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turn off (or weight) the pairwise interaction that would otherwise
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exist between 3 bonded atoms.
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In the formulas listed for each angle style, {theta} is the angle
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between the 3 atoms in the angle.
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:line
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Here is an alphabetic list of angle styles defined in LAMMPS. Click on
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the style to display the formula it computes and coefficients
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specified by the associated "angle_coeff"_angle_coeff.html command.
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Note that there are also additional angle styles submitted by users
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which are included in the LAMMPS distribution. The list of these with
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links to the individual styles are given in the angle section of "this
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page"_Section_commands.html#cmd_5.
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"angle_style none"_angle_none.html - turn off angle interactions
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"angle_style zero"_angle_zero.html - topology but no interactions
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"angle_style hybrid"_angle_hybrid.html - define multiple styles of angle interactions :ul
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"angle_style charmm"_angle_charmm.html - CHARMM angle
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"angle_style class2"_angle_class2.html - COMPASS (class 2) angle
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"angle_style cosine"_angle_cosine.html - cosine angle potential
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"angle_style cosine/delta"_angle_cosine_delta.html - difference of cosines angle potential
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"angle_style cosine/periodic"_angle_cosine_periodic.html - DREIDING angle
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"angle_style cosine/squared"_angle_cosine_squared.html - cosine squared angle potential
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"angle_style harmonic"_angle_harmonic.html - harmonic angle
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"angle_style table"_angle_table.html - tabulated by angle :ul
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:line
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[Restrictions:]
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Angle styles can only be set for atom_styles that allow angles to be
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defined.
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Most angle styles are part of the MOLECULE package. They are only
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enabled if LAMMPS was built with that package. See the "Making
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LAMMPS"_Section_start.html#start_3 section for more info on packages.
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The doc pages for individual bond potentials tell if it is part of a
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package.
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[Related commands:]
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"angle_coeff"_angle_coeff.html
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[Default:]
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angle_style none :pre
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