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<DIV><FONT face=Arial size=2>Dear Molpro users,</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I have a few questions about the MS-CASPT2 routine
implemented in MOLPRO 2006.1. </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>1.) I would get in the output:</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2> Recalculated energy
wrong<BR> Eigenvalue(2)=
-155.24783247539050<BR> D2(t).Heff.D2=
-155.24783247539030<BR> difference =
0.1989519660E-12 <BR> The recalculated energy D2(t).Heff.D2will be stored
in MSENERGY</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>If the energy stored in MSENERGY is incorrect, what
would be the correct MS-CASPT2 energy? </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>2.) Also, what is the difference between the
Heff-Brandow MS-CASPT2 energy and the Heff Sum Symmetrized MS-CASPT2
energies? Which one can I trust more? One of my coworkers is seeing
that states can change order from one definition to the other and the energy
gaps between states can also be different.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>3.) Do the transition dipole moments at the
end of the rs2 calculation correspond to single state CASPT2 or MS-CASPT2 if a
MS-CASPT2 calculation is performed?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>4.) Finally, I tried to do a MS-CASPT2
gradient calculation for one of the excited states. The input for the
MS-CASPT2 part is:</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial
size=2> rs2,root=2,mix=4,shift=0.3<BR> occ,17;closed,13;core,4<BR> state,
4<BR> maxiter,100<BR> forces</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I specified the gradient for state 2, but what I
see printed out in the output is:</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2> RSPT2 GRADIENT FOR STATE 1.1</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>It says it's calculating the gradient for state 1,
but I ask for state 2. Is this gradient for state 2 but mislabeled or is
this gradient for state 1?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Any insight to these questions would be
appreciated. Thanks</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Mitchell</FONT></DIV></BODY></HTML>