### Abstract

A zeroth-order wave function is constructed as an antisymmetrized product of two-electron group wave functions (geminals) expanded in disjunct but overlapping subspaces of basis orbitals. The geminals are obtained as exact solutions of the two-electron Schrödinger equations within the corresponding local basis sets, and thus give a fully correlated description of the two-electron chemical bonds coupled by inductive (Coulomb and exchange) effects, the latter being taken into account by an appropriate effective core operator. A second-quantized formulation [P. R. Surjn, Phys. Rev. A 30, 43 (1984), Part I] is applied where the wave functions of the individual bonds are represented by appropriate composite particle creation operators. Individual chemical bonds thus correspond to Bose quasiparticles composed of two electrons. Second-order perturbation theory is used for calculating interbond delocalization and dispersion effects. The treatment is based on a biorthogonal formulation [I. Mayer, Int. J. Quant. Chem. 23, 341 (1983); Ph. W. Payne, J. Chem. Phys. 77, 5630 (1982)] which makes the handling of interbond overlap very effective, and represents essentially a method of moments in the perturbation theory.

Original language | English |
---|---|

Pages (from-to) | 748-755 |

Number of pages | 8 |

Journal | Physical Review A |

Volume | 32 |

Issue number | 2 |

DOIs | |

Publication status | Published - 1985 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)
- Atomic and Molecular Physics, and Optics

### Cite this

**Interaction of chemical bonds. II. Ab initio theory for overlap, delocalization, and dispersion interactions.** / Surján, P.; Mayer, I.; Lukovits, I.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - Interaction of chemical bonds. II. Ab initio theory for overlap, delocalization, and dispersion interactions

AU - Surján, P.

AU - Mayer, I.

AU - Lukovits, I.

PY - 1985

Y1 - 1985

N2 - A zeroth-order wave function is constructed as an antisymmetrized product of two-electron group wave functions (geminals) expanded in disjunct but overlapping subspaces of basis orbitals. The geminals are obtained as exact solutions of the two-electron Schrödinger equations within the corresponding local basis sets, and thus give a fully correlated description of the two-electron chemical bonds coupled by inductive (Coulomb and exchange) effects, the latter being taken into account by an appropriate effective core operator. A second-quantized formulation [P. R. Surjn, Phys. Rev. A 30, 43 (1984), Part I] is applied where the wave functions of the individual bonds are represented by appropriate composite particle creation operators. Individual chemical bonds thus correspond to Bose quasiparticles composed of two electrons. Second-order perturbation theory is used for calculating interbond delocalization and dispersion effects. The treatment is based on a biorthogonal formulation [I. Mayer, Int. J. Quant. Chem. 23, 341 (1983); Ph. W. Payne, J. Chem. Phys. 77, 5630 (1982)] which makes the handling of interbond overlap very effective, and represents essentially a method of moments in the perturbation theory.

AB - A zeroth-order wave function is constructed as an antisymmetrized product of two-electron group wave functions (geminals) expanded in disjunct but overlapping subspaces of basis orbitals. The geminals are obtained as exact solutions of the two-electron Schrödinger equations within the corresponding local basis sets, and thus give a fully correlated description of the two-electron chemical bonds coupled by inductive (Coulomb and exchange) effects, the latter being taken into account by an appropriate effective core operator. A second-quantized formulation [P. R. Surjn, Phys. Rev. A 30, 43 (1984), Part I] is applied where the wave functions of the individual bonds are represented by appropriate composite particle creation operators. Individual chemical bonds thus correspond to Bose quasiparticles composed of two electrons. Second-order perturbation theory is used for calculating interbond delocalization and dispersion effects. The treatment is based on a biorthogonal formulation [I. Mayer, Int. J. Quant. Chem. 23, 341 (1983); Ph. W. Payne, J. Chem. Phys. 77, 5630 (1982)] which makes the handling of interbond overlap very effective, and represents essentially a method of moments in the perturbation theory.

UR - http://www.scopus.com/inward/record.url?scp=0007947981&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0007947981&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.32.748

DO - 10.1103/PhysRevA.32.748

M3 - Article

AN - SCOPUS:0007947981

VL - 32

SP - 748

EP - 755

JO - Physical Review A

JF - Physical Review A

SN - 2469-9926

IS - 2

ER -