From owner-chemistry@ccl.net Fri Nov 4 16:29:01 2011 From: "Cory Pye cpye * ap.smu.ca" To: CCL Subject: CCL:G: OPTIMIZATION PROBLEM Message-Id: <-45828-111104154916-1063-fV4R8CxEwlVrfle3iJseDw*server.ccl.net> X-Original-From: Cory Pye Content-Transfer-Encoding: 8bit Content-Type: TEXT/PLAIN; charset=X-UNKNOWN Date: Fri, 4 Nov 2011 16:56:57 -0300 (ADT) MIME-Version: 1.0 Sent to CCL by: Cory Pye [cpye**ap.smu.ca] Dear Partha, You either need to explicitly include the counterions in this 4- complex, and maybe also set periodic boundary conditions because you are trying to model a solid. I was trying to model the solution phase of a very similar anion with zinc instead of cadmium and found that it would also break apart. Another way to get around it is to model it as a solute by adding SCRF=CPCM. This may or may not work. What you are calculating is a naked gas-phase CdCl6 4- ion which most certainly doesn't exist. (Pye, Corbeil, Rudolph, PCCP 8 (2006) p5428) -Cory On Fri, 4 Nov 2011, partha kundu partha1kundu_+_yahoo.com wrote: > Hi, I have tried with scf=tight, but it didn't work. What is happening is 4 Cl atom is going far apart from each other. But its crystal structure shows it should be stable structure.Please help. regards. Partha ________________________________ > From: partha kundu To: CCL Subscribers Sent: Friday, 4 November 2011 9:13 AM Subject: Re: CCL:G: OPTIMIZATION PROBLEM Thank you Bradley for your help. I will try and let you know. regards. Partha. ________________________________ > From: Bradley Welch bwelch5]![slu.edu To: "Kundu, Partha Pratim " Sent: Thursday, 3 November 2011 5:57 PM Subject: CCL:G: OPTIMIZATION PROBLEM Have you tried using scf=tight. Usually scf=qc is used when the standard scf calculation fails.  Also, have you considered a slightly larger basis set on those chlorines? That seems like a very small basis set. Bradley Welch  On Thu, Nov 3, 2011 at 1:39 AM, Partha p kundu partha1kundu|yahoo.com wrote: >Sent to CCL by: "Partha p kundu" [partha1kundu-*-yahoo.com] >Dear All, >I have some problem in optimizing a geometry. My input file is the following. > > >%chk=cd.chk >%mem=200MW >%nproc=4 >#opt b3lyp/gen pseudo=read scf=qc nosym > >Title Card Required > > -4 1 > Cd                -1.05043015   -3.48046330    2.35727072 > Cl                 0.40206012   -5.72017854    2.49396286 > Cl                 1.00016821   -2.12566780    2.92423554 > Cl                -2.50292042   -1.24074806    2.22057858 > Cl                -0.43020500   -3.31734213   -0.23761836 > Cl                -1.67065530   -3.64358447    4.95215980 > Cl                -3.10102851   -4.83525880    1.79030589 > > Cl 0 > 3-21G > **** > Cd 0 > LANL2DZ > **** > > Cd > LANL2DZ > >Last few lines of my output is saying > >Linear equations converged to 2.037D-10 2.037D-09 after   3 iterations. > Search did not lower the energy significantly. > No lower point found -- try reversing direction. > Search did not lower the energy significantly. > No lower point found -- switch to scaled steepest descent. > Search did not lower the energy significantly. > Scaled steepest descent with Shift=0.000 failed. > Search did not lower the energy significantly. > Scaled steepest descent with Shift=0.025 failed. > Search did not lower the energy significantly. > Scaled steepest descent with Shift=0.050 failed. > Search did not lower the energy significantly. > Scaled steepest descent with Shift=0.075 failed. > Search did not lower the energy significantly. > No lower point found -- switch to steepest descent. > Search did not lower the energy significantly. > No lower point found -- run aborted. > Error termination via Lnk1e in C:\G03W\l508.exe at Thu Nov 03 11:48:56 2011. > > >Please help. Thanks in advance. >regards. >Partha.> >E-mail to subscribers: CHEMISTRY-x-ccl.net or use: >     http://www.ccl.net/cgi-bin/ccl/send_ccl_message > >E-mail to administrators: CHEMISTRY-REQUEST-x-ccl.net or use >     http://www.ccl.net/cgi-bin/ccl/send_ccl_message>     http://www.ccl.net/chemistry/sub_unsub.shtml> >     http://www.ccl.net/spammers.txt> > > ************* ! Dr. Cory C. Pye ***************** ! Associate Professor *** ** ** ** ! Theoretical and Computational Chemistry ** * **** ! Department of Chemistry, Saint Mary's University ** * * ! 923 Robie Street, Halifax, NS B3H 3C3 ** * * ! cpye_._crux.stmarys.ca http://apwww.stmarys.ca/~cpye *** * * ** ! Ph: (902)-420-5654 FAX:(902)-496-8104 ***************** ! ************* ! Les Hartree-Focks (Apologies to Montreal Canadien Fans)