From owner-chemistry@ccl.net Sun Jan 29 04:57:01 2012 From: "Thomas Exner thomas.exner__uni-konstanz.de" To: CCL Subject: CCL: Review MD sampling techniques Message-Id: <-46207-120129045541-1540-y74AjLoSK1YhPTmF+gDonA.:.server.ccl.net> X-Original-From: "Thomas Exner" Date: Sun, 29 Jan 2012 04:55:38 -0500 Sent to CCL by: "Thomas Exner" [thomas.exner===uni-konstanz.de] Dear CCLers: Could somebody please point me to reviews on new techniques for enhanced sampling like transition path sampling, replica exchange, steered and targeted MD, ... Thank you very much. Thomas From owner-chemistry@ccl.net Sun Jan 29 15:22:00 2012 From: "Jason D Acchioli jdacchio%x%gmail.com" To: CCL Subject: CCL:G: Unusual imaginary frequencies in ORCA Message-Id: <-46208-120129152038-2065-fMM5ZM31vH7bY/eL2tW0qA(0)server.ccl.net> X-Original-From: "Jason D'Acchioli" Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=iso-8859-1 Date: Sun, 29 Jan 2012 14:20:30 -0600 Mime-Version: 1.0 (Apple Message framework v1251.1) Sent to CCL by: "Jason D'Acchioli" [jdacchio^^^gmail.com] Rudolf, Thanks for the suggestion. We're still trying to figure this one out. Dmytro Bykov from the ORCA team is assisting, since this could also be an mpi problem. I won't know for sure, since the jobs with %scf convcheckmode 0 are still queuing on a remote server. My local calculations are the ones I'm trying to get to work. Jason On Jan 26, 2012, at 11:21 AM, Rudolf Herrmann rudolf.herrmann*|*physik.uni-augsburg.de wrote: > > Sent to CCL by: "Rudolf Herrmann" [rudolf.herrmann/./physik.uni-augsburg.de] > Hello Jason, > >> >> I'm having fits over the results of vibrational analyses of some >> organometallic species in ORCA 2.8. I've been running calcs on >> eta5-coordinated cyclopentadienyl and indenyl species, and keep coming > up >> with 12 imaginary vibrational modes. I've used Grid6 and Grid7, both > with VeryTightSCF, but I keep getting the same results. It is > interesting >> to note that in the ORCA output, I get the message: >> >> The first frequency considered to be a vibration is 20 >> The total number of vibrations considered is 31 >> >> Frequency number 20 is the first real frequency in the file. So do I >> ignore the imaginary vibrational frequencies? >> >> As an aside, I don't get the same vibrational results using Gaussian09 > or >> Gamess (Guassian calculates frequencies analytically, and Gamess using > semi-numerical methods). Please help! I'd like to be able to use ORCA > for >> these calcs, but I'm not sure why I keep getting imaginary modes! >> >> Jason >> > > I recently had a similar problem (due to diffuse basis functions) which I > reported to the ORCA list. Christoph Riplinger from the ORCA team noted > that I did not have good SCF convergence (Energy was converted but not > DP-MAX) which created the awkward frequency results. This could also be > your case. Maybe you can get better convergence by enforcing convergence > of all criteria with > > %scf convcheckmode 0 > maxiter 1000 > end > > Hope this helps, > > R. Herrmann. > > -- > Dr. Rudolf Herrmann > Institut für Physik > Universität Augsburg > >> PS The input file is: >> >> #Geometry optimization of eta-5 cp Fe complex; >> ! PAL8 RKS B3LYP/G ECP{SDD=Fe, SD(10,MDF)} def2-SVP VeryTightSCF Grid6 > moread NoFinalGrid >> >> %moinp "eta5_cp_fe_cat.inp_374.rat1.uwsp.gbw" >> >> !NumFreq >> >> %freq CentralDiff true end >> >> *xyz 1 1 >> C 0.971689 0.719105 1.589637 >> C 0.977762 -0.702168 1.606407 >> C -0.400171 1.150321 1.594023 >> C -1.221910 -0.005615 1.599239 >> C -0.374426 -1.161652 1.578488 >> H -0.749285 2.182860 1.606905 >> H -2.312277 -0.012064 1.604646 >> H -0.701906 -2.200605 1.595688 >> C -1.475017 -0.471787 -1.147495 >> C 0.341691 1.519012 -1.134741 >> C 1.139269 -1.047892 -1.139251 >> O -2.398822 -0.777188 -1.727932 >> O 0.566217 2.472894 -1.703417 >> O 1.854371 -1.711141 -1.715752 >> H 1.866252 -1.334418 1.615166 >> H 1.849699 1.364293 1.609103 >> Fe -0.002414 0.002238 -0.169933 >> * >> >> >> ******************************************* >> Jason D'Acchioli >> Assistant Professor of Chemistry >> University of Wisconsin-Stevens Point >> 2001 Fourth Avenue >> Stevens Point, WI 54481 >> http://chemdac.uwsp.edu> > ******************************************* Jason D'Acchioli Assistant Professor of Chemistry University of Wisconsin-Stevens Point 2001 Fourth Avenue Stevens Point, WI 54481 http://chemdac.uwsp.edu