IR absorption spectra of stretching C-H and C=O vibrations of CHF2Cl, C2H5C
l, and HCOOH molecules possessing a considerable store of vibrational energ
y are calculated. Calculations are based on simple one-by-one examination o
f all the vibrational states of a given energy. The range of validity of th
e computational method is discussed. The results of calculations are compar
ed on a qualitative level with the experimental data on IR multiple photon
dissociation of the aforesaid molecules.