Bond formation in diatomic transition metal hydrides: Insights from the analysis of domain‐averaged fermi holes

Abstract

The analysis of domain‐averaged Fermi holes (DAFHs) is used to provide detailed insights into the electron reorganization that accompanies the splitting of the bonding electron pairs in simple diatomic transition metal hydrides MH (M = Sc–Cr). The dissociation process is followed by monitoring the geometry dependence of the dominant DAFH functions, as well as their populations and overlaps. In addition to providing a highly appealing visual picture of the geometry‐induced changes in the bonding interactions, the DAFH approach clearly confirms the close link between the progress of the dissociation and the extent of electron sharing. The results of the various DAFH analyses straightforwardly reveal the anticipated close parallel in the nature of the MH bonds in the different systems studied, as well as the smooth character of the splitting of the associated shared electron pairs. In addition to a very basic resemblance between the different cases, subtle differences are revealed for individual systems. © 2012 Wiley Periodicals, Inc.

On the interpretation of domain averaged Fermi hole analyses of correlated wavefunctions

“…Depending on whether we are considering spin dependent or spinless DAFHs, we will be able to further assign these contributions to spin or spatial entanglement, as shown before. As noticed by Cooper and Ponec, 23 when n i is large enough, such a f i solution is usually accompanied by a partner f i 0 in O 0 that satisfies n i + n i 0 E 1. f i and f i 0 will not be in general equal, but approach that regime as correlation decreases and n i 0 -1 À n i .…”

“…Although from the conceptual point of view DAFH analyses are equally easy to apply to correlated or uncorrelated wavefunctions, most of the systems that have been studied to date [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] have been described either at the Hartree-Fock (HF) or (approximately) at the DFT levels. In both cases, the interpretation of DNOs and their associated occupation numbers is relatively easy, and the graphical representation of the DAFH orbitals allows us to summarize in a very efficient and clear way the nature and strength of the chemical bond between the O and O 0 regions.…”

Ni Oxidation State and Ligand Saturation Impact on the Capability of Octaazamacrocyclic Complexes to Bind and Reduce CO2

“…The Ni–C CO2 bond character was analysed using the domain-averaged fermi holes (DAFHs) [ 69 , 70 , 71 ] in the DGrid 5.1 program package [ 72 ] employing the B3LYP/6-311G* fchk files from the Gaussian16 program package. The localized orbitals (LOC) and their Mulliken atomic population analysis (MPA) were obtained via the ORCA 4.2.0. package [ 73 ].…”