forked from lijiext/lammps
60 lines
1.9 KiB
Plaintext
60 lines
1.9 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 ke command :h3
|
|
|
|
[Syntax:]
|
|
|
|
compute ID group-ID ke :pre
|
|
|
|
ID, group-ID are documented in "compute"_compute.html command
|
|
ke = style name of this compute command :ul
|
|
|
|
[Examples:]
|
|
|
|
compute 1 all ke :pre
|
|
|
|
[Description:]
|
|
|
|
Define a computation that calculates the translational kinetic energy
|
|
of a group of particles.
|
|
|
|
The kinetic energy or each particle is computed as 1/2 m v^2, where m
|
|
and v are the mass and velocity of the particle.
|
|
|
|
There is a subtle difference between the quantity calculated by this
|
|
compute and the kinetic energy calculated by the {ke} or {etotal}
|
|
keyword used in thermodynamic output, as specified by the
|
|
"thermo_style"_thermo_style.html command. For this compute, kinetic
|
|
energy is "translational" kinetic energy, calculated by the simple
|
|
formula above. For thermodynamic output, the {ke} keyword infers
|
|
kinetic energy from the temperature of the system with 1/2 Kb T of
|
|
energy for each degree of freedom. For the default temperature
|
|
computation via the "compute temp"_compute_temp.html command, these
|
|
are the same. But different computes that calculate temperature can
|
|
subtract out different non-thermal components of velocity and/or
|
|
include different degrees of freedom (translational, rotational, etc).
|
|
|
|
[Output info:]
|
|
|
|
This compute calculates a global scalar (the KE). This value can be
|
|
used by any command that uses a global scalar value from a compute as
|
|
input. See "Section_howto 15"_Section_howto.html#howto_15 for an
|
|
overview of LAMMPS output options.
|
|
|
|
The scalar value calculated by this compute is "extensive". The
|
|
scalar value will be in energy "units"_units.html.
|
|
|
|
[Restrictions:] none
|
|
|
|
[Related commands:]
|
|
|
|
"compute erotate/sphere"_compute_erotate_sphere.html
|
|
|
|
[Default:] none
|