title: Molecular electrostatic potential at the atomic sites in the effective core potential approximation.
abstract: Considering calculations of the molecular electrostatic potential at the atomic sites (MEP@AS) in the presence of effective core potentials (ECP), we found that the consequent use of the definition of MEP@AS based on the energy derivative with respect to nuclear charge leads to a formula that differs by one term from the result of simple application of Coulomb's law. We have developed a general method to analytically treat derivatives of ECP with respect to nuclear charge. Benchmarking calculations performed on a set of simple molecules show that our formula leads to a systematic decrease in the error connected with the introduction of ECP when compared to all-electron results. Because of a straightforward implementation and relatively low costs of the developed procedure we suggest to use it by default.
authors: Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland. lesiuk@tiger.chem.uw.edu.pl
authors: Michał
authors: M
authors: Lesiuk
authors: Janusz
authors: J
authors: Zachara