Lead
S.J.A. van Gisbergen, J.G. Snijders and E.J. Baerends, Calculating frequency-dependent hyperpolarizabilities using time-dependent density functional theory. Journal of Chemical Physics 109, 10644 (1998)
Suggested:
S.J.A. van Gisbergen, J.G. Snijders, and E.J. Baerends, Time-dependent Density Functional Results for the Dynamic Hyperpolarizability of C60. Physical Review Letters 78, 3097 (1997)
