Premium
Bond length and the electron density at the bond critical point: XX, ZZ, and CZ bonds (X = Li‐F, Z = Na‐Cl)
Author(s) -
Castillo Norberto,
Robertson Katherine N.,
Choi S. C.,
Boyd Russell J.,
Knop Osvald
Publication year - 2008
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.20795
Subject(s) - homonuclear molecule , bond length , chemistry , heteronuclear molecule , crystallography , valence electron , chemical bond , electron density , atom (system on chip) , bond energy , electron , molecule , physics , crystal structure , quantum mechanics , organic chemistry , computer science , embedded system
The aim was to investigate the relationship between the bond length and the electron density at the bond critical point in homonuclear XX and ZZ and heteronuclear CZ bonds (X = Li‐F, Z = Na‐Cl). The d ,ρ c pairs were obtained from 472 target bonds in DFT‐optimized (B3LYP/6‐311+G(d,p)) small molecular species. These species were selected arbitrarily but with a view to maximize the range widths WR for each atom combination. It was found that (i) with one clear exception, the d ( A − A ) means (A = X or Z) correlate linearly with the bond lengths d (A 2 ) of the respective diatomic molecules; (ii) the d ( A − A ) means correlate parabolically with n , the formal number of valence electrons in the atoms of the bond; and (iii) with increasing sample size N the ratio WR (ρ c )/ WR ( d ) appears to converge toward a representation f [ WR (ρ c )/ WR ( d )] N→∞ characteristic of A. Detailed analysis of the d ,ρ c relationship has shown that by and large simple power regression accounts best for the DFT data. The regression coefficients of d = a ρ c − band ρ c = α d − β ( b , β > 0) vary with n in a seemingly irregular manner but one that is consistent with simple chemical notions. The d (A 2 ) can be approximated in terms of multilinear MO electron occupancies. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008