A quantum molecular similarity analysis of changes in molecular electron density caused by basis set flotation and electric field application

Abstract

Quantum molecular similarity ͑QMS͒ techniques are used to assess the response of the electron density of various small molecules to application of a static, uniform electric field. Likewise, QMS is used to analyze the changes in electron density generated by the process of floating a basis set. The results obtained show an interrelation between the floating process, the optimum geometry, and the presence of an external field. Cases involving the Le Chatelier principle are discussed, and an insight on the changes of bond critical point properties, self-similarity values and density differences is performed.

Orbital-Based Interpretation of Electron Density Differences in Ne2 and Polarized Ne and Ne6+

“…Labeling of some contours in Figure a of ref is inconsistent with the symmetry. In addition, the field directions in refs and , unlike ref and the present work, are inconsistent with the signs of density differences in the outer regions.…”

“…We also examine density differences in a neon atom due to polarization by a nearby positive point charge. Density-difference contours due to uniform electric fields have been previously calculated for HF, , F 2 , and Ne . These density differences reverse sign repeatedly in the electric field direction.…”

Quantitative assessment of the effect of basis set superposition error on the electron density of molecular complexes by means of quantum molecular similarity measures

“…A better approach to quantify such differences is to use Quantum Molecular Similarity Measures 19, 20 (QMSM) between uncorrected and BSSE‐corrected densities. QMSM have been extensively used in the literature for the analysis of atomic and molecular one‐electron densities in a variety of contexts, namely to assess the effects of electron correlation on molecular densities 21, to quantify the electronic reorganization taking place in several reactions 22, 23, to analyze the quality of several basis sets 24, to evaluate the interactions of the electron density with external electric fields or continuous solvents 25, or even to compare contracted second‐order electron densities 26, 27.…”