arrow
Return

Equilibrium CO bond lengths

delete2012-09-01
delete53
PRE
AI
J
J. Demaison *
A
Attila G. Császár
DOI:10.1016/j.molstruc.2012.01.030delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
Based on a sample of 38 molecules, 47 accurate equilibrium CO bond lengths have been collected and analyzed. These ultimate experimental (r(e)(EX)), semiexperimental (r(e)(SE)), and Born-Oppenheimer (r(e)(BO)) equilibrium structures are compared to r(e)(BO) estimates from two lower-level techniques of electronic structure theory, MP2(FC)/cc-pVQZ and B3LYP/6-311+G(3df,2pd). A linear relationship is found between the best equilibrium bond lengths and their MP2 or B3LYP estimates. These (and similar) linear relationships permit to estimate the CO bond length with an accuracy of 0.002 angstrom within the full range of 1.10-1.43 angstrom, corresponding to single, double, and triple CO bonds, for a large number of molecules. The variation of the CO bond length is qualitatively explained using the Atoms in Molecules method. In particular, a nice correlation is found between the CO bond length and the bond critical point density and it appears that the CO bond is at the same time covalent and ionic. Conditions which permit the computation of an accurate ab initio Born-Oppenheimer equilibrium structure are discussed. In particular, the core-core and core-valence correlation is investigated and it is shown to roughly increase with the bond length. (c) 2012 Elsevier B.V. All rights reserved.
Keywords:
CO bond
Ab initio
Equilibrium structure
AIM theory

Journal

Journal of Molecular Structure cover
Journal of Molecular Structure
IF:
4.7
Papers:
3.5W
Citations:
6.6W

Organization

H
Hungarian Academy of Sciences
Scholars:
7.9K
Papers: 5.6K
Citations: 7.5K
U
universite de lille
Scholars:
2.7W
Papers: 2.0W
Citations: 15