State-averaged CASSCF and MRCI studies on the ground and low-lying singlet excited states of methylacetylene

摘要

In this work, the potential energy curves for the ground and low-lying singlet excited states of methylacetylene molecule are calculated at the state-averaged CASSCF level including nine roots. The vertical excitation energies, dipole moments and trnasition moments are also obtained at the equilibrium geometry for the low-lying singlet excited states at both CASSCF and MRCI levels. We have investigated the nature of the electronic transitions and the photolysis processes at different wavelengths as well as the vibronic effect for all the states.