Asymptotic energy levels of a rigid asymmetric top†.

The spectra of larger molecules are often observed to high rotational quantum numbers, and the asymptotic behaviour of the rotational energy levels is of interest. This paper is mainly concerned with the lowest-energy levels for high values of J. These tend to occur in oblate-type doublets, for which E. K. Gora gave an energy-level formula in 1965 that seems to be little known among pure rotational spectroscopists. In particular, the mean energies and splittings of these doublets are discussed and a new derivation of Gora's formula is described. [ABSTRACT FROM AUTHOR]