Electrostatic potentials Mulliken population analysis

Crystal can compute a number of properties, such as Mulliken population analysis, electron density, multipoles. X-ray structure factors, electrostatic potential, band structures, Fermi contact densities, hyperfine tensors, DOS, electron momentum distribution, and Compton profiles. 

First entry Mulliken population analysis second entry ESP electrostatic potential best fit, see Section 4.3. 

Population analysis in semiempirical methods fall into two categories. Methods including overlap in the Fock equations use the Mulliken population analysis. The majority of semiempirical methods uses the ZDO approximation, and the net charges are interpreted on the basis of symmetrically orthog-onalized AOs. It is pointed out that this interpretation is not exactly valid, because of truncation and empirical adjustment. But the corresponding nonsymmetrical orthogonalization is not uniquely defined. Charge models based on semiempirical wave functions play an important role in the calculation of molecular electrostatic potentials for reactivity. 

The q are atomic-centered charges that are computed in some reasonable manner, such as from a Mulliken population analysis [8-10,28], Stockholder analysis [30], fitting the electrostatic potential [30], or numerical integration [24,25], The term q(N) refers to the atomic charges computed for the original, iV-electron system q(N + 1) to charges computed for the system with an additional electron and q(N- 1) to an electron deficient system. 

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