Bond Length and Local Energy Density Property Connections for Non-transition- Metal-Oxide-Bonded Interactions
For a variety of molecules and Earth materials, the theoretical local kinetic energy density, G(rc), increases and the local potential energy density, V(rc), decreases as the MO bond lengths (M = first and second row metal atoms) decrease and electron density, ρ(rc), is localized at the bond critical points, rc. Despite claims that the ratio, G(rc)/ρ(rc), classifies bonded interactions as shared covalent when less than unity and closed shell ionic when greater than unity, the ratio was found to increase from 0.5 to 2.5 a.u. as the local electronic energy density H(rc) = G(rc) + V(rc) decreases and becomes progressively more negative. In any event, the ratio is indicated to be a measure of the character for a given M-O bond, the greater the ratio, the larger the value of ρ(rc), the smaller the coordination number of the M atom and the more covalent the bond. H(rc)/ρ(rc) vs. G(rc)/ρ(rc) scatter diagrams categorize the M-O bond data into domains with the H(rc)/ρ(rc) ratio tending to increase as the electronegativity of the M atoms increase. Estimated values of G(rc) and V(rc), using an expression based on gradient corrected electron gas theory, are in good agreement with theoretical values, particularly for bonded interactions involving second row M atoms. The agreement is poorer for the more covalent C-O and N-O bonds.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 895447
- Report Number(s):
- PNNL-SA-50799; 3273; KC0303020; TRN: US200702%%780
- Journal Information:
- Journal of Physical Chemistry A, 110(44):12259-12266, Journal Name: Journal of Physical Chemistry A, 110(44):12259-12266
- Country of Publication:
- United States
- Language:
- English
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