bond_style mm3 command¶
Syntax¶
bond_style mm3
Examples¶
bond_style mm3
bond_coeff 1 100.0 107.0
Description¶
The mm3 bond style uses the potential that is anharmonic in the bond as defined in (Allinger)
where \(r_0\) is the equilibrium value of the bond, and \(K\) is a prefactor. The anharmonic prefactors have units angstrom^(-n): -2.55 angstrom^(-1) and (7/12)2.55^2 angstrom^(-2). The code takes care of the necessary unit conversion for these factors internally. Note that the MM3 papers contains an error in Eq (1): (7/12)2.55 should be replaced with (7/12)2.55^2
The following coefficients must be defined for each bond type via the bond_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/distance^2)
\(r_0\) (distance)
Restrictions¶
This bond style can only be used if LAMMPS was built with the YAFF package. See the Build package doc page for more info.