RELIABILITY OF MEP AND MEP-DERIVED PROPERTIES COMPUTED FROM DFT METHODS FOR MOLECULES CONTAINING P, S AND CL

We present a systematic study on the reliability of different theoreti cal methods to represent the molecular electrostatic potential (MEP). and MEP-derived properties of prototypical compounds containing phosph orus. sulfur and chlorine. Calculations at the Hartree-Fock and Moller -Plesset up to fourth-order level of theory, as well as local. non-loc al and hybrid density functional computations were performed for a rep resentative set of neutral molecules. The study was carried out using different basis sets ranging from the medium-sized 6-31G(d) to the lar ge 6-31G(2d,2p) basis set, but in some test calculations more extended basis sets were also considered. The analysis of the results was perf ormed discussing separately the effect of the basis set and of the lev el of theory used to determine the molecular wavefunction on the relia bility of the MEP and MEP-derived properties.