manual   quickstart   instguide   update   basis
  Contents   Index  

9.3 Diatomic potential curve analysis

For the case that a table contains one or more potential energy functions for a diatomic molecule, with the first column containing bond lengths in Bohr or Ångstrom, it is possible to calculate spectroscopic constants using

DIATOMIC[,DEGREE=n][,MASS=m][,PRINT=p]

The data are fitted to a polynomial of degree $n$ (default is number of points minus 1, ie interpolation), and spectroscopic constants calculated using reduced mass $m$ expressed in u. Note that it is possible to constrain which bond lengths are used through the use of the RANGE subcommand.