Calculations of circular intensity differences in electric-field-induced second harmonic generation

Ab initio calculations of electric-field induced second-harmonic generation for chiral molecules are presented. The calculations employ cubic response theory and take into account electric-dipole, electric-quadrupole and magnetic-dipole interactions, which result in an intensity dependence on the helicity of the light. The circular intensity difference is calculated for the chiral molecules twisted ethylene, trans-1,2-dimethylcyclopropane and methyloxirane. The calculated circular intensity differences are small - being of the order of 10(-4)-10(-3) - but such electric-field induced second harmonic generation intensity dependencies should be experimentally detectable. (C) 1998 Elsevier Science B.V. All rights reserved.