C_beta = Atom('CH2')
C_epsilon = Atom('CH3')
C_gamma = Atom('CH2')
S_delta = Atom('S')
bonds = [Bond(C_gamma, C_beta), Bond(S_delta, C_gamma), Bond(C_epsilon, S_delta) ]
pdbmap = [('MET', {'SD': S_delta, 'CE': C_epsilon, 'CG': C_gamma, 'CB': C_beta, }, ), ]
pdb_alternative = {'HG1': '3HG', 'HB1': '3HB', }
name = 'met_sidechain'
opls_atom_type = { C_beta: 'C2', C_gamma: 'CQ', S_delta: 'S', C_epsilon: 'CW'  }
opls_charge = { C_beta: 0.0, C_gamma: 0.235, S_delta: -0.47, C_epsilon: 0.235  }
