From owner-chemistry-!at!-ccl.net Sat Jan  8 10:58:00 2011
From: "Close, David M. CLOSED\a/mail.etsu.edu" <owner-chemistry[#]server.ccl.net>
To: CCL
Subject: CCL:G: eliminate Spin Contamination for CCSD and MP2 in Gaussian
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X-Original-From: "Close, David M." <CLOSED]=[mail.etsu.edu>
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Date: Sat, 8 Jan 2011 15:56:27 +0000
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Sent to CCL by: "Close, David M." [CLOSED-x-mail.etsu.edu]
Yu:
  In the output there is the normal MP2 energy and then a PMP2 energy, followed by three values of S2. 
The first value of S2 is greater than 1?  That's from the normal MP2 run.  But the next value of S2 comes from the projected MP2 run, and this should be somewhat closer to 0.75.  Is it?
  Regards, Dave Close

-----Original Message-----
> From: owner-chemistry+closed==etsu.edu*_*ccl.net [mailto:owner-chemistry+closed==etsu.edu*_*ccl.net] On Behalf Of Decai Yu decaiyu23:-:yahoo.com
Sent: Friday, January 07, 2011 6:44 PM
To: Close, David M.
Subject: CCL:G: eliminate Spin Contamination for CCSD and MP2 in Gaussian


Sent to CCL by: Decai Yu [decaiyu23,yahoo.com]
Dear All,
 
 I have encountered significant spin-contamination with MP2
 and CCSD using Gaussian 09.
 Can anyone comment on how to eliminate the spin
 contamination using Gaussian?
 
 Your help is appreciated.
 
 Regards,
 
 Decai Yuhttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt