### Abstract

The symmetrised form of the operator Van Vleck perturbation theory is considered (the irreducible tensorial set theory is used as the mathematical basis of this consideration). General formulae which define spectroscopic rotational, centrifugal and resonance constants of molecules as functions of reduced matrix elements of vibrational operators are obtained. Algorithms for the ES-1055 computer have been derived on the basis of the formulae obtained, and a system of analytical calculations using the language 'REDUCE' has been created. The dyad and pentad of the CH_{4}-type molecule are considered for illustration. Formulae are obtained which connect spectroscopic and intramolecular constants not only for isolated but also for interacting vibrational states.

Original language | English |
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Article number | 009 |

Pages (from-to) | 997-1015 |

Number of pages | 19 |

Journal | Journal of Physics B: Atomic, Molecular and Optical Physics |

Volume | 22 |

Issue number | 7 |

DOIs | |

Publication status | Published - 1989 |

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### ASJC Scopus subject areas

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

### Cite this

*Journal of Physics B: Atomic, Molecular and Optical Physics*,

*22*(7), 997-1015. [009]. https://doi.org/10.1088/0953-4075/22/7/009