From owner-chemistry@ccl.net Mon May 11 15:36:01 2015 From: "Kirk Peterson kipeters##wsu.edu" To: CCL Subject: CCL: Making symmetry equivalence atomic orbitals Message-Id: <-51369-150511151436-23690-DAM2+wkGMI76wjuX4i/UQw-$-server.ccl.net> X-Original-From: Kirk Peterson Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=utf-8 Date: Mon, 11 May 2015 12:14:23 -0700 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\)) Sent to CCL by: Kirk Peterson [kipeters]=[wsu.edu] Dear Wirawan, yes, I believe you have the general understanding of the situation correct below. If codes would use full atomic symmetry this presumably wouldn't be an issue, but generally you’re stuck with calculating one component of a degenerate atomic state in the highest abelian group, hence for example px will be ‘different’ than py or pz. I usually use the MCSCF program in Molpro for symmetry equivalencing. In this case you just state-average the various HF states corresponding to the different open shells. This is not a black-box procedure though. best, -Kirk > On May 11, 2015, at 9:57 AM, Wirawan Purwanto wirawan0%yahoo.com wrote: > > > Sent to CCL by: "Wirawan Purwanto" [wirawan0{}yahoo.com] > Hi, > > Can someone give me a pointer to how to make "symmetry equivalenced" orbitals? I am not that familiar with this terminology, and in some papers this is mentioned without any citation. > > > This is my limited understanding of it: in the context of Hartree-Fock calculation of an isolated atom (say, ROHF calculation of Co atom), the five 3d orbitals ended up not having the same shape and energy because of the symmetry-broken configuration (3d7 4s2). The symmetry equivalenced 3d orbitals would then be obtained by somehow restoring the degenerate nature of these orbitals (which would raise the variational energy by a little bit). I think this can also be done for e.g. diatomic molecule where the pix-piy degeneracy could be broken due to open shell nature of the HF solution. > > > Here are my questions: > > 1. Is this understanding correct? > > 2. What are the step-by-step way to make the symmetry equivalenced orbitals from the usual ROHF or UHF orbitals? Any reference or program that can do this from a MO output given by a quantum chemistry program (e.g. GAMESS, molpro...whatever you like), assuming that I know the composition of the underlying AO basis (i.e. which function is 1s, ...2px,... 3dxy, and so on). > > > Thanks, > Wirawan> https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/cgi-bin/ccl/send_ccl_message&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=54de310d7862582eda966c6d2c71d66bde1c6e3fea01c4f40b19982b538b7872> https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/cgi-bin/ccl/send_ccl_message&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=54de310d7862582eda966c6d2c71d66bde1c6e3fea01c4f40b19982b538b7872> https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/chemistry/sub_unsub.shtml&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=1380054a1d4769a76447e2182c3504eb82028b1817887e8224886b3a9204e41a > > Before posting, check wait time at: https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=54d6471eed733b463ec2b43d12a25ddd9afb5d4361dd059371501a36415c05d8 > > Job: https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/jobs&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=c3ad93570c6221ea91e9c72209a730935d2630b74f13525cdbdde234b018c90d > Conferences: https://urldefense.proofpoint.com/v1/url?u=http://server.ccl.net/chemistry/announcements/conferences/&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=6abb77aeef4fd4cc86270aa36ec0a56ebd5847c2f44bdd26f89fa8f559a3a158 > > Search Messages: https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/chemistry/searchccl/index.shtml&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=dcfe1ae566f45531cba9239027bd6873e6c207e4497a468a9c7a4d2857b4d906> https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/spammers.txt&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=63d56e0721834b46dfd5afd37d4b9a04067aac191c6e8131b4d75f560a055b11 > > RTFI: https://urldefense.proofpoint.com/v1/url?u=http://www.ccl.net/chemistry/aboutccl/instructions/&k=EWEYHnIvm0nsSxnW5y9VIw%3D%3D%0A&r=ndj2Vta%2FisUMMOFOMobgvg%3D%3D%0A&m=MoY4K2vo2Vt6auAeG3H1BHQ%2BbZg6M4vlbxitj1iUZPo%3D%0A&s=f072ce5d9c9ac77d5f59959b010d70c233783b21fc79cf724bbcb99e9126b391 > >