Electron propagator theory

Hartree-Fock (HF), molecular orbital theory satisfies most of the criteria, but qualitative failures and quantitative discrepancies with experiment often render it useless. Methods that systematically account for electron correlation, employed in pursuit of more accurate predictions, often lack a consistent, interpretive apparatus. Among these methods, electron propagator theory [1] is distinguished by its retention of many conceptual advantages that facilitate interpretation of molecular structure and spectra [2, 3, 4, 5, 6, 7, 8, 9]. 

Electron propagator theory generates a one-electron picture of electronic structure that includes electron correlation. One-electron energies may be obtained reliably for closed-shell molecules with the P3 method and more complex correlation effects can be treated with renormalized reference states and orbitals. To each electron binding energy, there corresponds a Dyson orbital that is a correlated generalization of a canonical molecular orbital. Electron propagator theory enables interpretation of precise ab initio calculations in terms of one-electron concepts. 

The matrix Hfj would be the transpose of Hf, if it were Hermitian. The Hermiticity of the superoperator Hamiltonian has been a concern since the beginnings of the electron propagator theory (46,129). For a Hermitian spin ftee Hamiltonian (// ) the following relation can be written describing the Hermiticity problem,... 

It is also possible to employ highly correlated reference states as an alternative to methods that employ Hartree-Fock orbitals. Multiconfigu-rational, spin-tensor, electron propagator theory adopts multiconfigura-tional, self-consistent-field reference states [37], Perturbative corrections to these reference states have been introduced recently [38],... 

In this book, the experts who have developed and tested many of the currently used electronic structure procedures present an authoritative overview of the theoretical tools for the computation of thermochemical properties of atoms and molecules. The first two chapters describe the highly accurate, computationally expensive approaches that combine high-level calculations with sophisticated extrapolation schemes. In chapters 3 and 4, the widely used G3 and CBS families of composite methods are discussed. The applications of the electron propagator theory to the estimation of energy changes that accompany electron detachment and attachment processes follow in chapter 5. The next two sections of the book focus on practical applications of the aforedescribed... 

Y. Ohrn, G. Bom, Molecular electron propagator theory and calculations. Adv. Quantum Chem. 13, 1-88 (1981)... 

J.V. Ortiz, Energy gradients and effective density differences in electron propagator theory. J. Chem. Phys. 112, 56-68 (2000)... 

Y. Ohrn, G. Born, in P. O. Lowdin (Ed.), Electron propagator theory and calculations, Advances in Quantum Chemistry, Vol. 13, Academic Press, New York, 1981, p. 1. 

Yu. Dahnovsky, J.V. Ortiz, J. Chem. Ab initio electron propagator theory of molecular wires II. Multiorbital terminal description, Phys. 124 (2006) 144114. 

Ionization energy and electron affinity are critical discriminants of systemic reactivity and the one electron propagator theory /1,2/ has provided an effective route to their accurate calculation. The spectral representation of the matrix electron propagator... 

Flores-Moreno, R., Melin, J., Dolgounitcheva, O., Zakrzewski, V.G., Ortiz, J.V. Three approximations to the nonlocal and energy-dependent correlation potential in electron propagator theory. Int. J. Quantum Chem. 2010,110, 706-15. 

Ortiz, J.V., Zakrzewski, V.G. A test of partial third order electron propagator theory Vertical ionization energies of azabenzenes. J. Chem. Phys. 1996,105, 2762-69. 

The spectra of anionic mononucleotides (dXMP, where X = A, C, G, and T) [74] were rather poorly resolved for the first VDEs of dAMP , dCMP, and dTMP , whereas an error bar of 0.10 eV was determined for the VDE of dGMP . Theoretical VDE values obtained in the same paper as B3LYP energy differences between anionic and neutral states were about 0.5-0.8 eV off the experimental peak positions for dTMP, dCMP , and dAMP . No interpretation of other possible transitions was given. Excellent agreement with experimental energy values was achieved for VDEs of mononucleotide anions calculated with ab initio electron propagator theory [71, 75]. 

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