Ab initiocalculation of dynamic polarizability derivatives of hydrocarbon molecules

Abstract
Ab initio calculations of the derivative of the dynamic polarizability components of the hydrocarbons CH4, C2H2, C2H4 and C2H6 are performed within the random phase approximation. The results are compared with recent experimental data. The study shows the importance of using the frequency dependent polarizability in calculating non-resonance Raman intensities, particularly for some non-totally symmetric vibrations.