Gasteiger-Marsili empirical atomic partial charges

Definition:

- the contribution to the atomic charge on the a-th step of iteration of charge

- electronegativity of n–th orbital on i-th atom

, , , and - the ionization potentials and electron affinities of the neutral atom (superscript 0) and of the positive ion (superscript +), respectively.

References:

1. J. Gasteiger, M. Marsili, Tetrahedron Lett., 1978,  3181
2. J. Gasteiger, M. Marsili, Tetrahedron, 1980,  36, 3219-3228