74 lines
2.7 KiB
Plaintext
74 lines
2.7 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_modify command :h3
|
|
|
|
[Syntax:]
|
|
|
|
compute_modify compute-ID keyword value ... :pre
|
|
|
|
compute-ID = ID of the compute to modify :ulb,l
|
|
one or more keyword/value pairs may be listed :l
|
|
keyword = {extra/dof} or {extra} or {dynamic/dof} or {dynamic} :l
|
|
{extra/dof} value = N
|
|
N = # of extra degrees of freedom to subtract
|
|
{extra} syntax is identical to {extra/dof}, will be disabled at some point
|
|
{dynamic/dof} value = {yes} or {no}
|
|
yes/no = do or do not recompute the number of degrees of freedom (DOF) contributing to the temperature
|
|
{dynamic} syntax is identical to {dynamic/dof}, will be disabled at some point :pre
|
|
:ule
|
|
|
|
[Examples:]
|
|
|
|
compute_modify myTemp extra/dof 0
|
|
compute_modify newtemp dynamic/dof yes extra/dof 600 :pre
|
|
|
|
[Description:]
|
|
|
|
Modify one or more parameters of a previously defined compute. Not
|
|
all compute styles support all parameters.
|
|
|
|
The {extra/dof} or {extra} keyword refers to how many
|
|
degrees-of-freedom are subtracted (typically from 3N) as a normalizing
|
|
factor in a temperature computation. Only computes that compute a
|
|
temperature use this option. The default is 2 or 3 for "2d or 3d
|
|
systems"_dimension.html which is a correction factor for an ensemble
|
|
of velocities with zero total linear momentum. For compute
|
|
temp/partial, if one or more velocity components are excluded, the
|
|
value used for {extra} is scaled accordingly. You can use a negative
|
|
number for the {extra} parameter if you need to add
|
|
degrees-of-freedom. See the "compute
|
|
temp/asphere"_compute_temp_asphere.html command for an example.
|
|
|
|
The {dynamic/dof} or {dynamic} keyword determines whether the number
|
|
of atoms N in the compute group and their associated degrees of
|
|
freedom are re-computed each time a temperature is computed. Only
|
|
compute styles that calculate a temperature use this option. By
|
|
default, N and their DOF are assumed to be constant. If you are
|
|
adding atoms or molecules to the system (see the "fix
|
|
pour"_fix_pour.html, "fix deposit"_fix_deposit.html, and "fix
|
|
gcmc"_fix_gcmc.html commands) or expect atoms or molecules to be lost
|
|
(e.g. due to exiting the simulation box or via "fix
|
|
evaporate"_fix_evaporate.html), then this option should be used to
|
|
insure the temperature is correctly normalized.
|
|
|
|
NOTE: The {extra} and {dynamic} keywords should not be used as they
|
|
are deprecated (March 2017) and will eventually be disabled. Instead,
|
|
use the equivalent {extra/dof} and {dynamic/dof} keywords.
|
|
|
|
[Restrictions:] none
|
|
|
|
[Related commands:]
|
|
|
|
"compute"_compute.html
|
|
|
|
[Default:]
|
|
|
|
The option defaults are extra/dof = 2 or 3 for 2d or 3d systems and
|
|
dynamic/dof = no.
|