<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Dea<font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">r Victor,</span></font><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;"><br></span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">In your RSPT2 calculation the degeneracy in the 4F state is broken</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">because you use different CASPT2 methods. For the state 1.1, it is</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">single-root
CASPT2 method; whereas for the states 1.4~3.4, 1.6~3.6,</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">and 1.7~3.7, the method is multi-root CASPT2 in which both 4F and</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">4P are calculated.</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;"><br></span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">To get degenerate energies, please calculate 4F and 4P states</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">separately in RS2
by setting STATE. The same is also true for MRCI.</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;"><br></span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">Best wishes,</span></font></div><div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;">Wenli</span></font></div></td></tr></table><br>