Calculation dipole moments using Open Babel in Python

mol-dipoles.py

#!/usr/bin/env python

from __future__ import print_function

import sys
import os
import math

import pybel

# You can get a list of charge models
#  using `obabel -L charges`
methods = [ 'mmff94', 'gasteiger', 'eem2015bm' ]

for argument in sys.argv[1:]:
    filename, extension = os.path.splitext(argument)

    # read the molecule from the supplied file
    for mol in pybel.readfile(extension[1:], argument):

        for method in methods:
            # on the command-line, you can get partial charges like this
            # obabel CHF3.g03 -onul --partialcharge gasteiger --print
            cm = ob.OBChargeModel_FindType(method)
            cm.ComputeCharges(mol.OBMol)
            # but in C++ or Python we can get the dipole moment vector
            dipole = cm.GetDipoleMoment(mol.OBMol)
            moment = math.sqrt(dipole.GetX()**2+dipole.GetY()**2+dipole.GetZ()**2)

            print(filename, method, moment)