forked from lijiext/lammps
63 lines
2.2 KiB
Plaintext
63 lines
2.2 KiB
Plaintext
"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
|
|
|
|
compute group/group command :h3
|
|
|
|
[Syntax:]
|
|
|
|
compute ID group-ID group/group group2-ID :pre
|
|
|
|
ID, group-ID are documented in "compute"_compute.html command
|
|
group/group = style name of this compute command
|
|
group2-ID = group ID of second (or same) group :ul
|
|
|
|
[Examples:]
|
|
|
|
compute 1 lower group/group upper
|
|
compute mine fluid group/group wall :pre
|
|
|
|
[Description:]
|
|
|
|
Define a computation that calculates the total energy and force
|
|
interaction between two groups of atoms: the compute group and the
|
|
specified group2. The two groups can be the same. The interaction
|
|
energy is defined as the pairwise energy between all pairs of atoms
|
|
where one atom in the pair is in the first group and the other is in
|
|
the second group. Likewise, the interaction force calculated by this
|
|
compute is the force on the compute group atoms due to pairwise
|
|
interactions with atoms in the specified group2.
|
|
|
|
The energy and force are calculated by looping over a neighbor list of
|
|
pairwise interactions. Thus it can be inefficient to compute this
|
|
quantity too frequently.
|
|
|
|
[Output info:]
|
|
|
|
The interaction energy calculated by this compute is a scalar
|
|
quantity. The interaction force is a vector of length 3. Both the
|
|
scalar and vector values calculated by this compute are "extensive",
|
|
meaning they scale with the number of atoms in the simulation.
|
|
|
|
[Restrictions:]
|
|
|
|
Only pairwise interactions, as defined by the
|
|
"pair_style"_pair_style.html command, are included in this
|
|
calculation. Bond (angle, dihedral, etc) interactions between atoms
|
|
in the two groups are not included. Long-range interactions due to a
|
|
"kspace_style"_kspace_style.html command are also not included. Not
|
|
all pair potentials can be evaluated in a pairwise mode as required by
|
|
this compute. For example, 3-body potentials, such as
|
|
"Tersoff"_pair_tersoff.html and "Stillinger-Weber"_pair_sw.html cannot
|
|
be used. "EAM"_pair_eam.html potentials for metals only include the
|
|
pair potential portion of the EAM interaction, not the embedding
|
|
term.
|
|
|
|
[Related commands:] none
|
|
|
|
[Default:] none
|