From owner-chemistry@ccl.net Mon Aug 27 01:51:01 2012 From: "Andrew Yeung andrew.yeung(!)mail.chem.tamu.edu" To: CCL Subject: CCL:G: MOPAC/MOZYME PBC calculations Message-Id: <-47472-120826211022-13028-FqCPfZB23ZySwGnzasRVgg-$-server.ccl.net> X-Original-From: "Andrew Yeung" Content-Transfer-Encoding: 8bit Content-Type: text/plain;charset=utf-8; format="flowed" Date: Sun, 26 Aug 2012 20:10:13 -0500 MIME-Version: 1.0 Sent to CCL by: "Andrew Yeung" [andrew.yeung%x%mail.chem.tamu.edu] Thanks for getting back. I'll use the .arc files to generate new MOPAC input files. I suppose that MOPAC calculations are so fast that reading in force constants is not a huge advantage. I've turned to MOPAC because it is able to perform PBC calculations using semi-empirical hamiltonians, whereas Gaussian 09 is only able to use HF & DFT. Furthermore, G09 does not report enthalpies with a frequency calculation (and that must be done numerically). On Sun, 26 Aug 2012 12:12:48 -0400 "John McKelvey jmmckel::gmail.com" wrote: > > Sent to CCL by: John McKelvey [jmmckel]-[gmail.com] > Have you tried the latest version of Gaussian for all this as I >think > it also contains one of the latest MOPAC versions? > > In MOPAC itself you can use the DENOUT keyword to keep a >satisfactory > current density and then OLDENS to read YOUR_FILENAME.DEN in to >start > a subsequent job. > > You can carve out an input geometry from an archive file > (YOUR_FILENAME.ARC). To the best of my knowledge MOPAC does not > output intermediate geometries, and I am not aware that it outputs a > Hessian that can be read back in. > > Again, Gaussian included version of MOPAC can likely do all you >want. > > John McKelvey > > On Fri, Aug 24, 2012 at 6:27 PM, Andrew Yeung > andrew.yeung=-=chem.tamu.edu wrote: >> >> Sent to CCL by: Andrew Yeung [andrew.yeung^^chem.tamu.edu] >> Hi all >> >> I am doing a few PBC calculations on MOPAC, and I was hoping for >>some >> advise. >> >> Since the system is rather large (and I suppose the initial guess is >>poor), >> I cannot get SCF convergence unless I use the MOZYME keyword. The >>online >> manual (http://openmopac.net/manual/mozyme.html) gives some tips on >> multi-step jobs (MOZYME for geometry optimization, then MOPAC, then >>perhaps >> FORCE). >> >> Since my jobs have started already (MOZYME then FORCE), I want to >>let it >> run, and do the MOPAC equivalent of "geom=allcheck guess=read >>opt(readfc)" >> on the resultant output file(s). Is this possible? How else can I >>start a >> new calculation based on an old one? Should I edit the archive >>(.arc) file >> into a new MOPAC input file? >> >> Thanks for your comments. >> >> -- >> Andrew Yeung >> Donald J. Darensbourg Research Group >> Department of Chemistry, Texas A&M University >> 3255 TAMU >> College Station, TX 77843-3255 >> >> Tel: 979 845 4837 >> Fax: 979 845 >>0158http://www.ccl.net/chemistry/sub_unsub.shtmlConferences: >> http://server.ccl.net/chemistry/announcements/conferences/> >> > > > > -- > John McKelvey > 10819 Middleford Pl >Ft Wayne, IN 46818 > 260-489-2160 > jmmckel%x%gmail.com > > > > -= This is automatically added to each message by the mailing script >=- > To recover the email address of the author of the message, please >change> Conferences: >http://server.ccl.net/chemistry/announcements/conferences/> >