From chemistry-request@ccl.net Fri Oct 3 00:02:35 2003 Received: from qpcrkk.chem.tohoku.ac.jp (qpcrkk.chem.tohoku.ac.jp [130.34.112.204]) by server.ccl.net (8.12.8/8.12.8) with SMTP id h9342259021611 for ; Fri, 3 Oct 2003 00:02:03 -0400 Received: (qmail 19548 invoked from network); 3 Oct 2003 12:57:57 +0900 Received: from localhost (HELO qpcrkk.chem.tohoku.ac.jp) (127.0.0.1) by localhost with SMTP; 3 Oct 2003 12:57:57 +0900 Message-ID: <3F7CF3C5.9080609:at:qpcrkk.chem.tohoku.ac.jp> Date: Fri, 03 Oct 2003 12:57:57 +0900 From: HAJGATO Balazs User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: chemistry:at:ccl.net Subject: 2E" state Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, hits=-0.1 required=7.0 tests=USER_AGENT_MOZILLA_UA,X_ACCEPT_LANG version=2.55 X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) Dear CCL-ers, I am trying to calculate the single electron affinity of a molecule in the D3h pont group. The homo of the neutral molacule is E' and the lumo is E". I have calculated the neutral one and the orbital energies are perfect in almost all the cases. But I have problems with the single negative ion. I should be in 2E" state. So I have to use some multi reference method because single reference methods (MP2, CCSD and so on) give broken symmetry. So I tried CAS. I was able to calculate the neutral and the single negative ion and I have perfectly degenerated occupancies. (I used molcas, in Cs symmetry averaged ground and first excited state). But my problem is that I also need some dynamic correlation. I tried to calculate MR-SDCI with molcas (using supersymmetry) with RASSCF and MRCI modules, but I get always wrong occupancies (no degeneracy in energies/occupancies). I also tried to use molpro (version 2000.1) but in case of cas I get wrong occupancies. Using MR-SDCI for the negative ion with the necessary additional reference symmetries I still get wrong occupancies. I also tried ACES2 mr-bw-ccsd method with averaged ground and first excited states but I dont know to much about the mr-bwccsd method and with using diffuse basis set the CCSD dont converge. (and sometimes simply dumps core the program). My question is what kind of onther programs /methods are available to calculate the 2E" state? Is mr-bwccsd is capable to calculate doublet states as well? I see only singlet,triplet, and quintet mr-bwccsd calculations. Any suggestions are welcome. Regards, B. Hajgato