Vibrational theory of polyatomic molecules: energy levels of CH4/CD4 and CH3Cl/CD3Cl

A relatively simple model, previously used to describe polyatomic vibrations of nonlinear triatomic molecules, has been employed to evaluate the fundamentals, first overtones and combination bands of CX4 and CX3Cl (X = H, D). Relatively good agreement is obtained between calculated and observed frequencies. Interesting splittings of certain overtone and combination bands result from these calculations.