forked from lijiext/lammps
63 lines
2.1 KiB
Plaintext
63 lines
2.1 KiB
Plaintext
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"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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compute pe/atom command :h3
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[Syntax:]
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compute ID group-ID pe/atom keyword ... :pre
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ID, group-ID are documented in "compute"_compute.html command
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pe/atom = style name of this compute command
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zero or more keywords may be appended
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keyword = {pair} or {bond} or {angle} or {dihedral} or {improper} :ul
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[Examples:]
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compute 1 all pe/atom
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compute 1 all pe/atom pair
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compute 1 all pe/atom pair bond :pre
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[Description:]
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Define a computation that computes the per-atom potential energy for
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each atom in a group. See the "compute pe"_compute_pe.html command if
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you want the potential energy of the entire system. The per-atom
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energies can be accessed as scalar values by any command that uses
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per-atom computes, e.g. the "dump custom"_dump.html command or "fix
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ave/spatial"_fix_ave_spatial.html command or "fix
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ave/atom"_fix_ave_atom.html command. See "this
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section"_Section_howto.html#4_15 for an overview.
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The per-atom energy is calulated by the various pair, bond, etc
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potentials defined for the simulation. If no extra keywords are
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listed, then the potential energy is the sum of pair, bond, angle,
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dihedral, and improper energy. If any extra keywords are listed, then
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only those components are summed to compute the potential energy.
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Note that the energy of each atom is due to its interaction with all
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other atoms in the simulation, not just with other atoms in the group.
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For an energy contribution produced by a small set of atoms (e.g. 4
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atoms in a dihedral or 3 atoms in a Tersoff 3-body interaction), that
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energy is assigned in equal portions to each atom in the set.
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E.g. 1/4 of the dihedral energy to each of the 4 atoms.
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The "dihedral_style charmm"_dihedral_charmm.html style calculates
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pairwise interactions between 1-4 atoms. The energy contribution of
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these terms is included in the pair energy, not the dihedral energy.
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[Restrictions:] none
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[Related commands:]
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"compute pe"_compute_pe.html, "compute
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stress/atom"_compute_stress_atom.html
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[Default:] none
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