Geometrical optimization for strictly localized structures

Recently we proposed the block localized wavefunction (BLW) approach which takes the advantages of valence bond theory and molecular orbital theory and defines the wavefunctions for resonance structures based on the assumption that all electrons and orbitals are partitioned into a few subgroups. In this work, we implement the geometrical optimization of the BLW method based on the algorithm proposed by Gianinetti and coworkers. Thus, we can study the conjugation effect on not only the molecular stability, but also the molecular geometry. With this capability, the π conjugation effect in trans-polyenes C2nH2n+2 (n=2–5) as well as in formamide and its analogs are studied by optimizing their delocalized and strictly localized forms with the 6-31G(d) and 6-311+G(d,p) basis sets. Although it has been well presumed that the π resonance shortens the single bonds and lengthens the double bonds with the delocalization of π electrons across the whole line in polyenes, our optimization of the strictly localized stru...

[1]  Antonino Famulari,et al.  Implementation of gradient-optimization algorithms and force constant computations in BSSE-free direct and conventional SCF approaches , 1998 .

[2]  T. Thomas,et al.  Why are organic acids stronger acids than organic alcohols , 1986 .

[3]  Jiali Gao,et al.  Cation−π Interactions: An Energy Decomposition Analysis and Its Implication in δ-Opioid Receptor−Ligand Binding , 2002 .

[4]  G. W. Wheland,et al.  Resonance in Organic Chemistry , 1956 .

[5]  Mark S. Gordon,et al.  General atomic and molecular electronic structure system , 1993, J. Comput. Chem..

[6]  Y. Mo,et al.  Energy decomposition analysis of intermolecular interactions using a block-localized wave function approach , 2000 .

[7]  Michael J. S. Dewar,et al.  The molecular orbital theory of organic chemistry , 1969 .

[8]  Xavier Fradera,et al.  The Lewis Model and Beyond , 1999 .

[9]  W. Goddard.  Improved Quantum Theory of Many-Electron Systems. I. Construction of Eigenfunctions of S^ 2 Which Satisfy Pauli's Principle , 1967 .

[10]  Wei Wu,et al.  Delocalization in allyl cation, radical, and anion , 1996 .

[11]  D. B. Chesnut.  A comparative quantum mechanical study of bond separation energies as a measure of cyclic conjugation , 1995, J. Comput. Chem..

[12]  Paul von Ragué Schleyer,et al.  Nucleus-Independent Chemical Shifts:  A Simple and Efficient Aromaticity Probe. , 1996, Journal of the American Chemical Society.

[13]  Fokke Dijkstra,et al.  Gradients in valence bond theory , 1999 .

[14]  G. Frenking,et al.  Resonance Stabilization in Allyl Cation, Radical, and Anion , 1994 .

[15]  Karl Jug,et al.  Aromaticity as a multi-dimensional phenomenon , 1991 .

[16]  C. Breneman,et al.  Resonance interactions in acyclic systems. 1. Energies and charge distributions in allyl anions and related compounds , 1990 .

[17]  P. Schleyer,et al.  Why are carboxylic acids stronger acids than alcohols? The electrostatic theory of Siggel–Thomas revisited , 2000 .

[18]  R. Janoschek.  Has the benzene molecule an extra stability , 1991 .

[19]  J. V. Lenthe,et al.  1,3,5-Cyclohexatriene captured in computro; the importance of resonance , 2002 .

[20]  M.J.S. Dewar,et al.  A re-evaluation of conjugation and hyperconjugation: The effects of changes in hybridisation on carbon bonds , 1959 .

[21]  L. Pauling.  The Nature Of The Chemical Bond , 1939 .

[22]  Wei Wu,et al.  Theoretical Resonance Energies of Benzene, Cyclobutadiene, and Butadiene , 1994 .

[23]  N. D. Epiotis.  Applications of molecular orbital-valence bond theory in chemistry , 1983 .

[24]  Y. Mo,et al.  A simple electrostatic model for trisilylamine: Theoretical examinations of the n ->sigma* negative hyperconjugation, p pi -> d pi bonding, and stereoelectronic interaction , 1999 .

[25]  Péter G. Szalay,et al.  High-level electron correlation calculations on formamide and the resonance model , 1997 .

[26]  Alan R. Katritzky,et al.  Aromaticity as a Quantitative Concept. 1. A Statistical Demonstration of the Orthogonality of "Classical" and "Magnetic" Aromaticity in Five- and Six-Membered Heterocycles , 1989 .

[27]  L. Curtiss,et al.  Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint , 1988 .

[28]  Y. Mo,et al.  Theoretical analysis of electronic delocalization , 1998 .

[29]  Gg Balint-Kurti,et al.  Lecture notes in Chemistry , 2000 .

[30]  K. Jug,et al.  Delocalization Energy of .pi. Electrons as an Index for Aromaticity of Polycyclic Hydrocarbons , 1994 .

[31]  Anan Wu,et al.  Efficient algorithm for the spin-free valence bond theory. I. New strategy and primary expressions , 1998 .

[32]  David L. Cooper,et al.  Valence Bond Theory , 2002 .

[33]  Mikhail N. Glukhovtsev,et al.  Aromaticity and Antiaromaticity: Electronic and Structural Aspects , 1994 .

[34]  L. J. Schaad,et al.  Hueckel molecular orbital .pi. resonance energies. Benzenoid hydrocarbons , 1971 .

[35]  Mario Raimondi,et al.  Modification of the Roothaan equations to exclude BSSE from molecular interaction calculations , 1996 .

[36]  M. Nascimento,et al.  A generalized multistructural wave function , 1993 .

[37]  Haijun Jiao,et al.  What is aromaticity? , 1996, J. Chem. Inf. Comput. Sci..

[38]  Frank Weinhold,et al.  Natural hybrid orbitals , 1980 .

[39]  Otto Exner,et al.  Resonance energy in benzene and ethene derivatives in the gas phase as a measure of resonance ability of various functional groups , 2000 .