Method of solving the inverse spectral problem

The authors describe a method of solving the inverse spectral problem which is applicable to free molecules as well as to molecules in a medium. We give a criterion for the uniqueness of the definition of the force matrix. This criterion links the necessary number of normal proper vibrations of a molecule with a number of necessary form parameters. We calculate the force matrix of tetrahedral molecules CH/sub 4/, CD/sub 4/, CT/sub 4/. When we use zero-point values for frequencies of normal vibrations the relative discrepancy in the corresponding force-matrix elements does not exceed 0.3%.