Pariser-parr calculations and electro-optical effects in benzene

Abstract

Pariser-Parr calculations were done for the singlet states of benzene using singly and doubly excited configurations. Good agreement is obtained with the experimental locations of the 1B2u, 1B 1u, and 1E1u states as well as the oscillator strength of the 1A1g→1E1u transition. The 1E2g state is calculated to be 0.5 eV above the 1E1u state and its photodissociation can be deduced from its bond orders. A possible assignment of the 1A 1g→1E2g transition is discussed. On the basis of this simple model, electro-optical effects are small, such as the Stark shift for the 1E1u and 1B1u states.