\(\renewcommand{\AA}{\text{Å}}\)
angle_style mm3 command
Syntax
angle_style mm3
Examples
angle_style mm3
angle_coeff 1 100.0 107.0
Description
The mm3 angle style uses the potential that is anharmonic in the angle as defined in (Allinger)
where \(\theta_0\) is the equilibrium value of the angle, and \(K\) is a prefactor. The anharmonic prefactors have units \(\deg^{-n}\), for example \(-0.014 \deg^{-1}\), \(5.6 \cdot 10^{-5} \deg^{-2}\), …
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:
\(K\) (energy)
\(\theta_0\) (degrees)
\(\theta_0\) is specified in degrees, but LAMMPS converts it to radians internally; hence \(K\) is effectively energy per radian^2.
Restrictions
This angle style can only be used if LAMMPS was built with the YAFF package. See the Build package doc page for more info.
Default
none