Abstract
A comprehensive theoretical investigation of the third‐order susceptibilities for the nonlinear optical processes dc Kerr and dc electric‐field‐induced second‐harmonic generation is reported for H2 and D2. Accurate wave functions of the J ames–Coolidge‐type, which account for electronic correlation, are utilized and particular attention is given to the effects of vibration. Results for both the parallel and perpendicular components of the susceptibilities are given for λ=∞, 10 640, 6943, 6328, 5900, 5145, and 4880 Å. These are sufficient to enable a direct comparison with certain experimental data and, in general, the agreement is within the expected error bounds.