The four lowest-lying singlet electronic states of SF2 have been Studied by using the CASSCF, CASPT2, and MRSDCI methods. The geometries of excited states were optimized by using the CASSCF and CASPT2 methods. The CASPT2 and MRSDCI adiabatic (T-0) excitation energy calculations, using the CASPT2 geometries of the ground state and the excited states, predict that the X(1)A(1), 1(1)B(1), 1(1)A(2), and 2(1)B(1) states are the four lowest-lying singlet states. The A and B states of SF2 are assigned to 1(1)B(1) and 2(1)B(1), respectively. However the B' state, which was recently reported to lie between A and B, cannot be assigned. (C) 2002 Elsevier Science B.V. All rights reserved.