thermo.dipole module

thermo.dipole.dipole_moment(CASRN, AvailableMethods=False, Method=None)[source]

This function handles the retrieval of a chemical’s dipole moment. Lookup is based on CASRNs. Will automatically select a data source to use if no Method is provided; returns None if the data is not available.

Prefered source is ‘CCCBDB’. Considerable variation in reported data has found.


CASRN : string



dipole : float

Dipole moment, [debye]

methods : list, only returned if AvailableMethods == True

List of methods which can be used to obtain dipole moment with the given inputs

Other Parameters:

Method : string, optional

The method name to use. Accepted methods are ‘CCCBDB’, ‘MULLER’, or ‘POLING’. All valid values are also held in the list dipole_methods.

AvailableMethods : bool, optional

If True, function will determine which methods can be used to obtain the dipole moment for the desired chemical, and will return methods instead of the dipole moment


A total of three sources are available for this function. They are:

  • ‘CCCBDB’, a series of critically evaluated data for compounds in [R214216], intended for use in predictive modeling.
  • ‘MULLER’, a collection of data in a group-contribution scheme in [R215216].
  • ‘POLING’, in the appendix in [3].

This function returns dipole moment in units of Debye. This is actually a non-SI unit; to convert to SI, multiply by 3.33564095198e-30 and its units will be in ampere*second^2 or equivalently and more commonly given, coulomb*second. The constant is the result of 1E-21/c, where c is the speed of light.


[R214216](1, 2) NIST Computational Chemistry Comparison and Benchmark Database NIST Standard Reference Database Number 101 Release 17b, September 2015, Editor: Russell D. Johnson III
[R215216](1, 2) Muller, Karsten, Liudmila Mokrushina, and Wolfgang Arlt. “Second- Order Group Contribution Method for the Determination of the Dipole Moment.” Journal of Chemical & Engineering Data 57, no. 4 (April 12, 2012): 1231-36. doi:10.1021/je2013395.
[R216216]Poling, Bruce E. The Properties of Gases and Liquids. 5th edition. New York: McGraw-Hill Professional, 2000.


>>> dipole_moment(CASRN='64-17-5')