Syntax:
angle_style quartic
Examples:
angle_style quartic angle_coeff 1 129.1948 56.8726 -25.9442 -14.2221
Description:
The quartic angle style uses the potential
where theta0 is the equilibrium value of the angle, and K is a prefactor. 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 command as in the example above, or in the data file or restart files read by the read_data or read_restart commands:
Theta0 is specified in degrees, but LAMMPS converts it to radians internally; hence the units of K are in energy/radian^2.
Restrictions:
This angle style can only be used if LAMMPS was built with the USER_MISC package. See the Making LAMMPS section for more info on packages.
Related commands:
Default: none