The formyl cyanide files HCOCN.* describe a simple example of an asymmetric
top molecule. It is shown in the files HFS.* how to fit hyperfine splitting
in case the values for the splittings are given instead of the frequencies
of the individual hyperfine components.
Note: In case of overlapping hyperfine
components one has to take care that the sum of the weights of the
respective components is 0.5 – at least after normalization of the whole
difference to 1 (see HFS.fit).
The data were taken from the following article:
M. Bogey, C. Demuynck, J. L. Destombes and Y. Vallee,
Millimeter-Wave Spectrum of Formyl Cyanide, HCOCN:
Centrifugal Distortion and Hyperfine Structure Analysis,
J. Mol. Spectrosc. 172 (2003) 344–351. Read the
abstract.