Noble-gas compounds: A general procedure of bonding analysis

This paper accounts for a general procedure of bonding analysis that is, expectedly, adequate to describe any type of interaction involving the noble-gas (Ng) atoms. Building on our recently proposed classification of the Ng-X bonds (X = binding partner) [New J. Chem. 44, 15536 (2020)], these contacts are first distinguished into three types, namely, A, B, or C, based on the topology of the electron energy density H(r) and on the shape of its plotted form. Bonds of type B or C are, then, further assigned as B-loose (B-l) or B-tight (B-t) and C-loose (C-l) or C-tight (C-t) depending on the sign that H(r) takes along the Ng-X bond path located from the topological analysis of rho(r), particularly at around the bond critical point (BCP). Any bond of type A, B-l/B-t, or C-l/C-t is, finally, assayed in terms of contribution of covalency. This is accomplished by studying the maximum, minimum, and average value of H(r) over the volume enclosed by the low-density reduced density gradient (RDG) isosurface associated with the bond (typically, the RDG isosurface including the BCP) and the average rho(r) over the same volume. The bond assignment is also corroborated by calculating the values of quantitative indices specifically defined for the various types of interactions (A, B, or C). The generality of our taken approach should encourage its wide application to the study of Ng compounds.

Automated summary

This paper presents a general procedure for bonding analysis in interactions involving noble-gas atoms, providing a comprehensive method for studying noble-gas compounds by classifying and evaluating the covalent contribution of different types of bonds based on the topology and electron energy density.