From owner-chemistry@ccl.net Sat Apr 26 13:32:00 2014 From: "nilanjan dey ndey3071:_:gmail.com" To: CCL Subject: CCL: TD-DFT calculation Message-Id: <-49962-140426101654-4725-o4N6Vr/LLP1DK2ccv8Og1w]_[server.ccl.net> X-Original-From: "nilanjan dey" Date: Sat, 26 Apr 2014 10:16:53 -0400 Sent to CCL by: "nilanjan dey" [ndey3071-*-gmail.com] which excited state should I consider for FMO calculation from TD-DFT. Always the 1st excited state or the excited state having non-zero f value....In my case I got like this.... Excited State 1: ?Spin -A 1.0877 eV 1139.86 nm f=0.0000 88B -> 96B 0.10044 89B -> 96B -0.14166 94B -> 96B 0.99800 This state for optimization and/or second-order correction. Copying the excited state density for this state as the 1-particle RhoCI density. Excited State 2: ?Spin -A 1.2630 eV 981.68 nm f=0.0000 95B -> 96B 0.99811 Excited State 3: ?Spin -A 1.7633 eV 703.12 nm f=0.0243 94A -> 98A 0.11447 88B -> 96B 0.10357 90B -> 96B -0.39009 91B -> 96B 0.86896 92B -> 96B 0.10442 From owner-chemistry@ccl.net Sat Apr 26 14:07:00 2014 From: "Jan Labanowski janl()speakeasy.net" To: CCL Subject: CCL: Open and closed shell singlet energy difference Message-Id: <-49963-140426134722-32250-qPJQZTh3jhbG9rk2o3T/+w . server.ccl.net> X-Original-From: "Jan Labanowski" Date: Sat, 26 Apr 2014 13:47:20 -0400 Sent to CCL by: "Jan Labanowski" [janl() speakeasy.net] Posted on behalf of "Teck Lip Dexter Tam" Hi, I used crystal structure of my molecule to calculate close- and open-shell singlet ground state energies. I have gotten the open-shell singlet to be 0.28 cal-mol^-1 lower than the close-shell singlet. Usually papers report in the kcal-mol^-1 range for such calculation. My question is, is there a minimum total energy difference to say a calculation is valid and for my open-shell singlet ground state to hold? Best, Dexter From owner-chemistry@ccl.net Sat Apr 26 19:26:00 2014 From: "Alan Shusterman alan]|[reed.edu" To: CCL Subject: CCL: Open and closed shell singlet energy difference Message-Id: <-49964-140426191421-25435-Z++kACqIuFv0PqdvZsMcig,+,server.ccl.net> X-Original-From: Alan Shusterman Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Date: Sat, 26 Apr 2014 16:14:08 -0700 MIME-Version: 1.0 Sent to CCL by: Alan Shusterman [alan]-[reed.edu] 0.28 cal/mol falls in the range of numerical imprecision. Have you looked at the open-shell model to see if there is significant spin density anywhere? If there isn't then I suspect that the open-shell model is essentially the same as the closed-shell model. Alan On 4/26/14 10:47 AM, Jan Labanowski janl()speakeasy.net wrote: > Sent to CCL by: "Jan Labanowski" [janl() speakeasy.net] > Posted on behalf of "Teck Lip Dexter Tam" Hi, > > I used crystal structure of my molecule to calculate close- and open-shell singlet ground state energies. I have gotten the open-shell singlet to be 0.28 cal-mol^-1 lower than the close-shell singlet. Usually papers report in the kcal-mol^-1 range for such calculation. My question is, is there a minimum total energy difference to say a calculation is valid and for my open-shell singlet ground state to hold? > > Best, > Dexter> > -- Alan Shusterman Chemistry Department Reed College 3203 SE Woodstock Blvd. Portland, OR 97202-8199 503-517-7699 http://blogs.reed.edu/alan/ "Nature doesn't make long speeches." Lao Tzu 23