Multiwfn interface

Mulitiwfn is an open-source quantum chemistry code full of wavefunction and density analysis features.

ASH features a simple wrapper interface that allows you to quickly use some Multiwfn functionality in an ASH script to e.g. create density or MO Cube-file.

Multiwfn can be compiled or binaries downloaded for the requested platform. It is probably best to use the noGUI version of Multiwfn.

You can provide multiwfndir (path to Multiwfn containing the Multiwfn binary) to ASH or alternatively ASH will search for the "Multiwfn" binary in the PATH.

def multiwfn_run(moldenfile, fchkfile=None, multiwfndir=None, option='density',
mrccoutputfile=None, mrccdensityfile=None,
grid=3, numcores=1, fragmentfiles=None, fockfile=None, openshell=False):

The multiwfn_run function requires a Molden file as input and can also read an FChk file.

The grid parameter controls the density grid used for the calculation. The default is 3, which is a fine grid. The type of Multiwfn job to perform is controlled by the option parameter. The default option is 'density', for creating a Cubefile of the electron density. Other options are: 'nocv' for NOCV analysis (see NOCV_Multiwfn in Electronic structure analysis for more information). 'hirshfeld' for Hirshfeld population analysis.

For reading a Molden-file produced by MRCC one should use the mrccoutputfile and mrccdensityfile options.