Dear Molpro user, I found the molpro 2009.1 can only use the casscf or mrci, but not caspt2(rs2c or rs2) to calculate the spin-orbit coupling (SOC). As we know, for some systems, the mrci is not affordable. I need the caspt2 to calculate the SOC. Does some users want to share some experiences with me about it? Best regards, lydia