Exploring bonding patterns of molecular systems using quantum mechanical bond multiplicities

• Autorzy: Mrozek, J. , Nalewajski, R.F. , Michalak, A.
• Języki publikacji: EN

Abstrakty

EN

One of the fundamental chemical concepts, the structural formula of a chemical species, which visualizes bonding patterns in a given molecular system, can also given a more flexible and quantified form in terms of alternative quantum-mechanical measures of bond-orders. The recently developed difference approach, based upon the one-determinantal wavefunction [Hartree-Fock(HF) and Kohn-Sham (KS) theories], compares the charge-and-bond-order matrix in a molecule (P) and that in the separated atoms limit (P(0), SAL) defined in the orthogonal basis set of atomic functions. In this approach the atomic and diatomic contibutions to the molecularly averaged difference between these matrices, /2 = 1/2tr[P(P(0) - P)], are used to define bond multiplicities. THe main purpose of this work is to examine the overall performance of such KS and HF bonding indices, when applied to the set of chemically well defined reference systems, and to use them to investigate bond-orders in more challenging molecules, which have recently been the subject of independent studies. Manifestations of changing bond ionicity by these effective bond-orders are examined for a series of diatomics. Some methodological aspects associated with alternative SAL choices are discussed and tested.

Słowa kluczowe

EN

quantum mechanical bond multiplicities (structural formulas); one-determinantal differences approach; Hartree-Fock and Kohn-Sham theories; dilithium salt of dihydroxyacetylene; dodecachloro-cyclohexane; bis(my-carbonyl-dichloro-palladium)

• Czasopismo: Polish Journal of Chemistry
• Rocznik: 1998
• Tom: Vol. 72, nr 7S
• Strony: 1779-1791
• Opis fizyczny: Bibliogr. 31 poz., tab.

Twórcy

autor

Mrozek, J.

autor

Nalewajski, R.F.

autor

Michalak, A.

• K.Gumiński Department of Theoretical Chemistry Jagiellonian University R. Ingardena 3 30-060 Cracow Poland