Instead of performing an energy calculation, only calculate transition matrix elements between wavefunctions saved on records readc1 and readc2. See section 6.13 for a list of available operators and their corresponding keywords. If no operator names are specified, the dipole transition moments are calculated.
If option BIORTH is given, the two wavefunctions may use different orbitals. However, the number of active and inactive orbitals must be the same in each case. Note that BIORTH is not working for spin-orbit matrix elements. Under certain conditions it may happen that biorthogonalization is not possible, and then an error message will be printed.