The excited AOrsquo;s 2sH, 2pH, 3sX, and 3pXthinsp; (X=C, N, O, and F) have been included in the basis used in the INDOndash;MOndash;CI method. This results in virtual orbitals that are largely a combination of valencehyphen;shell AOrsquo;s, Rydberg AOrsquo;s, or a mixture of the two kinds of AOrsquo;s. Then the molecular excited state is described largely as a valence, a Rydberg, or a mixed valencendash;Rydberg state. Both the singletlarr;singlet and tripletlarr;singlet Rydberg as well as the valencehyphen;shell transitions along with their oscillator strengths have been calculated for a number of prototype molecules. The lowest energy transitions in simple unsaturated organic molecules are essentially valencehyphen;shell transitions. However, in the case of saturated molecules these lowest lying transitions have appreciable contribution from the Rydberg configurations. The Rydberg character of the other excited states also are generally correctly brought out. In addition, the singletndash;triplet splittings are described in a rather satisfactory manner.
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