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Orders of Magnitude and Symmetry in Molecular Spectroscopy

  1. Takeshi Oka

Published Online: 15 SEP 2011

DOI: 10.1002/9780470749593.hrs074

Handbook of High-resolution Spectroscopy

Handbook of High-resolution Spectroscopy

How to Cite

Oka, T. 2011. Orders of Magnitude and Symmetry in Molecular Spectroscopy. Handbook of High-resolution Spectroscopy. .

Author Information

  1. University of Chicago, Department of Chemistry and Department of Astronomy and Astrophysics, Chicago, IL, USA

Publication History

  1. Published Online: 15 SEP 2011


Considerations of the order of magnitude and the symmetry of various intramolecular interactions form the foundation of molecular spectroscopy. They are related and they together make molecular spectroscopy transparent and tidy. In this chapter, they are discussed starting from the very fundamental. The order of magnitude has not been discussed in any previous textbooks of molecular spectroscopy. The symmetry has been discussed in many textbooks and discussions here are limited to the rotational and nuclear spin states and its application to forbidden rotational transitions and the stability of nuclear spin modifications (ortho-, para- etc.).


  • molecular spectroscopy;
  • order of magnitude;
  • fine structure constant;
  • Born–Oppenheimer constant;
  • symmetry;
  • permutation–inversion group;
  • parity;
  • molecular rotation;
  • spin modification;
  • forbidden rotational transition