Comment on ‘‘Relations between microscopic and macroscopic lowest-order optical nonlinearities of molecular crystals with one- or two-dimensional units’’

An algebraic error in an earlier paper [J. Zyss and J. L. Oudar, Phys. Rev. A 26, 2028 (1982)] led to an interpretation regarding the desirable polarizability characteristics of a molecule for second-harmonic generation in crystals which is opposite to that actually desired. Optimum response is obtained from crystals comprised of molecules with significant in-plane polarizabilities.