Molecular dynamics (MD) simulations of epsilon(L) (k, omega), the frequency (omega) and wave vector (k) dependent longitudinal component of the dielectric permittivity tensor, a quantity of importance in several theories of solvation dynamics and charge transfer reactions, is reported for three molecular liquids: CH3CN, CO2, and C6H6, represented by nonpolarizable model potentials. In order to study dielectric properties of nondipolar fluids we use, instead of the conventional approach which relates epsilon(L) (k, omega) to longitudinal dipole density fluctuations, a more general approach of Raineri and co-workers which expresses this quantity in terms of charge density fluctuations. The two formulations are compared in the case of acetonitrile to assess the model dependence of epsilon(L) (k, omega). We find that at finite k, 1/epsilon(L) (k), where epsilon(L) (k) = epsilon(L) (k, 0) is the static longitudinal permittivity, exhibits several similar features for all three liquids: A partial cancellation between single-molecule and pair charge density fluctuation correlations at small k, their constructive interference at intermediate k and the lack of molecular pair correlation contributions at large k. We also find that the extended reference interaction site model (XRISM) integral equations provide an excellent approximation to epsilon(L) (k) of all three liquids. We use the fact 1/epsilon(L) (k) is a polynomial in k(2) at small k to determine the static dielectric constant epsilon(0) = epsilon(L) (k=0) of acetonitrile and obtain a value in good agreement with e0 evaluated by more conventional methods. We find that intermolecular correlations contribute the most to the dielectric properties of CH3CN and the least to those of CO2. In the range of k most relevant to solvation (k less than or equal to 1 Angstrom(-1)), the pair component of the charge-charge time correlation function Phi(qq) (k, t) is negative, partially cancelling the positive single-molecule component. The extent of cancellation varies with k and the strength of intermolecular electrostatic interactions, leading to significant qualitative differences in the behavior of Fqq (k, t) for polar and nondipolar liquids: In this k range, Fqq (k, t) in acetonitrile decays more slowly as k increases, while the opposite k-ordering is seen in the two nondipolar liquids. We use our results for epsilon(L) (k(min), omega), where k(min) is the smallest wave vector accessible in our simulation, to calculate the far-IR (infrared) absorption coefficient alpha(omega) of acetonitrile and find that it agrees well with alpha(omega) obtained from the transverse permittivity component, epsilon(T) (k(min), omega), indicating that the bulk limit for this quantity has been reached.