forked from lijiext/lammps
59 lines
1.6 KiB
Plaintext
59 lines
1.6 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
|
|
|
|
angle_style sdk command :h3
|
|
|
|
[Syntax:]
|
|
|
|
angle_style sdk :pre
|
|
angle_style sdk/omp :pre
|
|
|
|
[Examples:]
|
|
|
|
angle_style sdk
|
|
angle_coeff 1 300.0 107.0 :pre
|
|
|
|
[Description:]
|
|
|
|
The {sdk} angle style is a combination of the harmonic angle potential,
|
|
|
|
:c,image(Eqs/angle_harmonic.jpg)
|
|
|
|
where theta0 is the equilibrium value of the angle and K a prefactor,
|
|
with the {repulsive} part of the non-bonded {lj/sdk} pair style
|
|
between the atoms 1 and 3. This angle potential is intended for
|
|
coarse grained MD simulations with the CMM parametrization using the
|
|
"pair_style lj/sdk"_pair_sdk.html. Relative to the pair_style
|
|
{lj/sdk}, however, the energy is shifted by {epsilon}, to avoid sudden
|
|
jumps. Note that the usual 1/2 factor is included in K.
|
|
|
|
The following coefficients must be defined for each angle type via the
|
|
"angle_coeff"_angle_coeff.html command as in the example above:
|
|
|
|
K (energy/radian^2)
|
|
theta0 (degrees) :ul
|
|
|
|
Theta0 is specified in degrees, but LAMMPS converts it to radians
|
|
internally; hence the units of K are in energy/radian^2.
|
|
The also required {lj/sdk} parameters will be extracted automatically
|
|
from the pair_style.
|
|
|
|
[Restrictions:]
|
|
|
|
This angle style can only be used if LAMMPS was built with the
|
|
USER-CG-CMM package. See the "Making
|
|
LAMMPS"_Section_start.html#start_3 section for more info on packages.
|
|
|
|
[Related commands:]
|
|
|
|
"angle_coeff"_angle_coeff.html, "angle_style
|
|
harmonic"_angle_harmonic.html, "pair_style lj/sdk"_pair_sdk.html,
|
|
"pair_style lj/sdk/coul/long"_pair_sdk.html
|
|
|
|
[Default:] none
|