"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
