Topological analysis of the molecular electrostatic potential

The topology of the molecular electrostatic potential of 18 molecules, calc ulated in the framework of Kohn-Sham density functional theory, is studied. For the location of the different kinds of critical points a newly develop ed search algorithm is applied. A chemical interpretation of the critical p oints in terms of lone pairs, pi bonds, hybrid orbitals and other electroni c structure elements is suggested. A Poincare-Hopf relationship for the mol ecular electrostatic potential is derived, connecting electronic structure elements and electrostatic reactivity via the topology of the molecular ele ctrostatic potential. (C) 1999 American Institute of Physics. [S0021-9606(9 9)30334-2].