class ForceField(atoms, bonds, angles, dihedrals=None, imdihedrals=None, pairs=None)[source]

Bases: monty.json.MSONable

Stores force field information.

  • atoms (Dict) – store atomic mass for each atom name. { “custom atom name”: atom name, ... }
  • bonds (Dict) – store the bond distance and spring constant for each bond. { (“atom name1”, “atom name2”): [spring const, distance], ... }
  • angles (Dict) – store the bond angle and spring constant. { (“atom name1”, “atom name2”, “atom name3”): [spring const, angle], ... }
  • dihedrals (Dict) – store dihedral paramters. { (“atom name1”, “atom name2”, “atom name3”, “atom name4”): [val1, val2, ...], ... }
  • imdihedrals (Dict) – store improper dihedral information. Similar to dihedrals.
  • pairs (Dict) – store pair coefficient info. { (“atom name1”, “atom name2”): [val1, val2, ..], ... }
static from_file(filename)[source]

Read in forcefield parameters from yaml file and return Forcefield object. Basically read in atom name mappings(key=’Atoms’), bond coefficients(key=’Bond Coeffs’), angle coefficients(key=’Angle Coeffs’), pair coefficients(key=’Pair Coeffs’), dihedral coefficients(key=’Dihedral Coeffs’) and the improper dihedral coefficients(key=’Improper Coeffs’).

Parameters:filename (string) –
Returns:ForceField object