### Abstract

The significance of hybrid atomic orbitals is discussed in the context of perturbation theories of the chemical bond. It is emphasized that the correct choice of hybrids is essential in obtaining sufficiently accurate zeroth order (strictly localized) solution, representing a "Pauling-point" in chemical-bond theories. It is proved that for some small molecules, e.g. for first-row hydrides in small basis sets, there may exist a set of non-orthogonal exactly localized (two-centre) occupied molecular orbitals which span the same subspace and have the same energy as do the canonical MOs, but have no tails on other atoms. Although this statement cannot be generalized to larger molecules or larger basis sets, it still suggests that the apparent interbond delocalization (tails) predicted by various perturbative schemes does not necessarily correspond to physical interbond interaction, but, to a large extent, it may be a consequence of using poor atomic hybrids. As examples, non-orthogonal strictly localized MOs are reported for CH_{4} and NH_{3} in the STO-3G basis set.

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

Pages (from-to) | 95-104 |

Number of pages | 10 |

Journal | Journal of Molecular Structure: THEOCHEM |

Volume | 169 |

Issue number | C |

DOIs | |

Publication status | Published - 1988 |

### Fingerprint

### ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Computational Theory and Mathematics
- Atomic and Molecular Physics, and Optics

### Cite this

**The role of hybridization in perturbative bond theories : The existence of exact strictly localized orbitals in small molecules.** / Surján, P.

Research output: Contribution to journal › Article

}

TY - JOUR

T1 - The role of hybridization in perturbative bond theories

T2 - The existence of exact strictly localized orbitals in small molecules

AU - Surján, P.

PY - 1988

Y1 - 1988

N2 - The significance of hybrid atomic orbitals is discussed in the context of perturbation theories of the chemical bond. It is emphasized that the correct choice of hybrids is essential in obtaining sufficiently accurate zeroth order (strictly localized) solution, representing a "Pauling-point" in chemical-bond theories. It is proved that for some small molecules, e.g. for first-row hydrides in small basis sets, there may exist a set of non-orthogonal exactly localized (two-centre) occupied molecular orbitals which span the same subspace and have the same energy as do the canonical MOs, but have no tails on other atoms. Although this statement cannot be generalized to larger molecules or larger basis sets, it still suggests that the apparent interbond delocalization (tails) predicted by various perturbative schemes does not necessarily correspond to physical interbond interaction, but, to a large extent, it may be a consequence of using poor atomic hybrids. As examples, non-orthogonal strictly localized MOs are reported for CH4 and NH3 in the STO-3G basis set.

AB - The significance of hybrid atomic orbitals is discussed in the context of perturbation theories of the chemical bond. It is emphasized that the correct choice of hybrids is essential in obtaining sufficiently accurate zeroth order (strictly localized) solution, representing a "Pauling-point" in chemical-bond theories. It is proved that for some small molecules, e.g. for first-row hydrides in small basis sets, there may exist a set of non-orthogonal exactly localized (two-centre) occupied molecular orbitals which span the same subspace and have the same energy as do the canonical MOs, but have no tails on other atoms. Although this statement cannot be generalized to larger molecules or larger basis sets, it still suggests that the apparent interbond delocalization (tails) predicted by various perturbative schemes does not necessarily correspond to physical interbond interaction, but, to a large extent, it may be a consequence of using poor atomic hybrids. As examples, non-orthogonal strictly localized MOs are reported for CH4 and NH3 in the STO-3G basis set.

UR - http://www.scopus.com/inward/record.url?scp=36148995410&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=36148995410&partnerID=8YFLogxK

U2 - 10.1016/0166-1280(88)80252-5

DO - 10.1016/0166-1280(88)80252-5

M3 - Article

VL - 169

SP - 95

EP - 104

JO - Computational and Theoretical Chemistry

JF - Computational and Theoretical Chemistry

SN - 2210-271X

IS - C

ER -