Molecular properties of excited electronic states: The ã ³A″ and à ¹A″ states of formaldehyde

Ab initio self-consistent-field wavefunctions and molecular properties have been calculated for the three lowest electronic states of H₂CO. For the ground state, a variety of basis sets were used, the largest being an uncontracted Gaussian basis: C(11s 7p 2d), O(11s 7p 2d), H(6s 1p). For the excited states, the above basis was contracted to C(7s 5p 2d), O(7s 5p 2d), H(4s 1p). Ground state molecular properties agree well with the earlier theoretical study of Neumann and Moskowitz, and with available experimental data. The z components (along the CO bond axis) of the excited state dipole moments have been measured, and the present a priori predictions reproduce experiment rather closely. Other properties reported include quadrupole moments, octupole moments, and electric field gradients.