2006-09-22 00:22:34 +08:00
|
|
|
"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
|
|
|
|
|
|
|
|
|
|
improper_style hybrid command :h3
|
|
|
|
|
|
|
|
|
|
[Syntax:]
|
|
|
|
|
|
|
|
|
|
improper_style hybrid style1 style2 ... :pre
|
|
|
|
|
|
|
|
|
|
style1,style2 = list of one or more improper styles :ul
|
|
|
|
|
|
|
|
|
|
[Examples:]
|
|
|
|
|
|
|
|
|
|
improper_style hybrid harmonic helix
|
|
|
|
|
improper_coeff 1 harmonic 120.0 30
|
|
|
|
|
improper_coeff 2 cvff 20.0 -1 2 :pre
|
|
|
|
|
|
|
|
|
|
[Description:]
|
|
|
|
|
|
|
|
|
|
The {hybrid} style enables the use of multiple improper styles in one
|
|
|
|
|
simulation. An improper style is assigned to each improper type. For
|
|
|
|
|
example, impropers in a polymer flow (of improper type 1) could be
|
|
|
|
|
computed with a {harmonic} potential and impropers in the wall
|
|
|
|
|
boundary (of improper type 2) could be computed with a {cvff}
|
|
|
|
|
potential. The assignment of improper type to style is made via the
|
|
|
|
|
"improper_coeff"_improper_coeff.html command or in the data file.
|
|
|
|
|
|
|
|
|
|
In the improper_coeff command, the first coefficient sets the improper
|
|
|
|
|
style and the remaining coefficients are those appropriate to that
|
|
|
|
|
style. In the example above, the 2 improper_coeff commands would set
|
|
|
|
|
impropers of improper type 1 to be computed with a {harmonic}
|
|
|
|
|
potential with coefficients 120.0, 30 for K, X0. Improper type 2
|
|
|
|
|
would be computed with a {cvff} potential with coefficients 20.0, -1,
|
|
|
|
|
2 for K, d, n.
|
|
|
|
|
|
2007-03-21 04:14:06 +08:00
|
|
|
If the improper {class2} potential is one of the hybrid styles, it
|
|
|
|
|
requires additional AngleAngle coefficients be specified in the data
|
|
|
|
|
file. These lines must also have an additional "class2" argument
|
|
|
|
|
added after the improper type. For improper types which are assigned
|
|
|
|
|
to other hybrid styles, use the style name (e.g. "harmonic")
|
|
|
|
|
appropriate to that style. The AngleAngle coeffs for that improper
|
|
|
|
|
type will then be ignored.
|
|
|
|
|
|
2006-09-28 03:12:31 +08:00
|
|
|
An improper style of {none} can be specified as an argument to
|
|
|
|
|
improper_style hybrid and the corresponding improper_coeff commands,
|
|
|
|
|
if you desire to turn off certain improper types.
|
2006-09-22 00:22:34 +08:00
|
|
|
|
2007-06-26 08:03:39 +08:00
|
|
|
[Restrictions:]
|
|
|
|
|
|
|
|
|
|
This improper style can only be used if LAMMPS was built with the
|
|
|
|
|
"molecular" package (which it is by default). See the "Making
|
|
|
|
|
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
2006-09-22 00:22:34 +08:00
|
|
|
|
|
|
|
|
[Related commands:]
|
|
|
|
|
|
|
|
|
|
"improper_coeff"_improper_coeff.html
|
|
|
|
|
|
|
|
|
|
[Default:] none
|
