# free_atom_volumes¶

psi4.driver.p4util.free_atom_volumes(wfn, **kwargs)[source]

Computes free-atom volumes using MBIS density partitioning. The free-atom volumes are computed for all unique (inc. basis set) atoms in a molecule and stored as wavefunction variables, MBIS FREE ATOM n VOLUME. Free-atom densities are computed at the same level of theory as the molecule, and we use unrestricted references as needed in computing the ground-state.

The free-atom volumes are used to compute volume ratios in routine MBIS computations

Parameters:

wfn (Wavefunction) – The wave function associated with the molecule, method, and basis for atomic computations