<html><body bgcolor="#FFFFFF"><div>The workaround from Gerald is to follow your</div><div>CAS with an rhf step but set maxit=1. In </div><div>the subsequent uccsd you'll need to set the</div><div>nocheck option. </div><div><br></div><div>Kirk</div><div><br>Sent from my iPhone</div><div><br>On Aug 10, 2011, at 10:01 AM, binjiang.nju <<a href="mailto:binjiang.nju@gmail.com">binjiang.nju@gmail.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div>
<div>
<div><font color="#000000" size="4" face="Calibri">Dear all,</font></div>
<div><font size="4" face="Calibri"></font> </div>
<div style="TEXT-INDENT: 2em"><font size="4" face="Calibri">I am trying to do a
uccsd(t) calculation with CASSCF orbitals in Molpro.2010.1, it will be useful
when two quasi-degenerate states exist and sometimes improve
the convergence, comparing to the
uccsd(t)/hf strategy. </font></div>
<div style="TEXT-INDENT: 2em"><font size="4" face="Calibri"></font> </div>
<div style="TEXT-INDENT: 2em"><font size="4" face="Calibri">It works fine when I use
only normal uccsd(t) option, but it fails when I use uccsd(t)-f12 option. I
have tried to change the basis set, active space, as well as the type
of CASSCF orbitals (Natural, Canonical), all of these do not help. Then I
find some information for such problem, but still no suitalbe answer.
</font></div>
<div style="TEXT-INDENT: 2em"><font size="4" face="Calibri"></font> </div>
<div style="TEXT-INDENT: 2em"><font size="4" face="Calibri">Gerald Knizia has
mentioned that the F12 methods do request RHF reference functions, but he would
try to fix this. (I cite his words in the following, hopefully he would not
mind)</font></div>
<div style="TEXT-INDENT: 2em"><font size="4" face="Calibri"></font><font size="4" face="Calibri"></font> </div><span style="WIDOWS: 2; TEXT-TRANSFORM: none; TEXT-INDENT: 0px; BORDER-COLLAPSE: separate; FONT: medium 'Times New Roman'; WHITE-SPACE: normal; ORPHANS: 2; LETTER-SPACING: normal; COLOR: rgb(0,0,0); WORD-SPACING: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px" class="Apple-style-span"><span style="FONT-FAMILY: arial, helvetica, sans-serif; COLOR: rgb(111,111,111); FONT-SIZE: 12px" class="Apple-style-span"><strong>
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<div id="post_message_2"><font size="4" face="Calibri">Dear all,<br>the
reason that F12 methods request RHF reference functions is related
to<span class="Apple-converted-space"> </span><br>subtle issues
with the the internal consistency of the respective methods<span class="Apple-converted-space"> </span><br>(open-shell vs
closed-shell and the four combinations of density fitted vs<span class="Apple-converted-space"> </span><br>non-density fitted
reference/correlation calculations).<br>If I am not mistaken, for
the CCSD methods (and maybe the non-density<span class="Apple-converted-space"> </span><br>fitted MP2-F12 methods)
the current restrictions can be lifted such that<span class="Apple-converted-space"> </span><br>general reference
functions are allowed. I will try to fix this and to<span class="Apple-converted-space"> </span><br>provide a patch for the
current production version.<br>--<span class="Apple-converted-space"> </span><br>Gerald
Knizia<br>_______________________________________________<br>___________________________________________________<br></font></div></div></td></tr></tbody></table></div></div></form></td></tr></tbody></table></strong></span></span>
<div><font size="4" face="Calibri"> I am wondering that whether this issue
has been solved or not. Is there any way to use CASSCF wavefunctions for
UCCSD(t)-F12 calculations? Does anyone has other advise? Thanks in
advance.</font></div>
<div><font size="4" face="Calibri"></font> </div>
<div><font size="4" face="Calibri">Best regards</font></div>
<div><font size="4" face="Calibri">Bin</font></div>
<div> </div>
<div> </div>
<div align="left"><font color="#c0c0c0" size="2" face="Verdana">2011-08-10</font></div><font size="2" face="Verdana">
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<div><font color="#c0c0c0" size="2" face="Verdana"><span id="_FlashSignName">binjiang.nju</span></font></div></font></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>Molpro-user mailing list</span><br><span><a href="mailto:Molpro-user@molpro.net">Molpro-user@molpro.net</a></span><br><span><a href="http://www.molpro.net/mailman/listinfo/molpro-user">http://www.molpro.net/mailman/listinfo/molpro-user</a></span><br></div></blockquote></body></html>