In the case of multi-state multi-reference CASPT2 calculations, only a single run is needed:
{RS2,MIX=nstates, options
STATE,nstates}
Example: MS-MR-CASPT2 calculation for LiF
Input: lif_mr_mscaspt2.com Output: lif_mr_mscaspt2.out
This produces the plot
One can clearly see that this gives smoother potentials than the SS-SR-CASPT2 calculation in the previous section. Also, the avoided crossing is shifted to longer distances, which is due to the improvement of the electron affinity of F.