  In this letter, we analyze the dipole-dipole correlations obtained from the
molecular dynamics simulations for strongly- and weakly-polar model liquids. As
a result, we found that cross-correlations contribution to the systems total
dipole moment correlation function, which is directly measured in the
dielectric spectroscopy experiment, is negligible for weakly-polar liquids. In
contrast, the cross-correlations term dominates over the self-correlations one
for examined strongly polar-liquid. Consequently, our studies strongly support
the interpretation of the dielectric spectra nature of the glass forming
liquids, recently proposed by Pabst et al.
