Syntax:
improper_style harmonic
Examples:
improper_style harmonic improper_coeff 1 100.0 0
Description:
The harmonic improper style uses the potential
where X is the improper angle, X0 is its equilibrium value, and K is a prefactor. Note that the usual 1/2 factor is included in K.
The following coefficients must be defined for each improper type via the improper_coeff command as in the example above, or in the data file or restart files read by the read_data or read_restart commands:
X0 is specified in degrees, but LAMMPS converts it to radians internally; hence the units of K are in energy/radian^2.
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 for more info on packages.
Related commands:
Default: none