def _parse_bond_line( line ):
    """Parse an AMBER frcmod BOND line and return relevant parameters in a dictionary. AMBER uses length and force constant, with the factor of two dropped. Here we multiply by the factor of two before returning. Units are angstroms and kilocalories per mole per square angstrom."""

    tmp = line.split()
    params = {}
    params['smirks'] = tmp[0]
    params['k'] = str(2*float(tmp[1]))
    params['length'] = tmp[2]
    return params