Re: CCL:frequency calculations using MP2 in Gaussian

[Alessandro Contini <alessandro.contini |-at-| unimi.it>]

Hi Dario, the problem is that your Hard Disk is not so big as you think;
 the scratck files for an MP2 calculation could easyly reach and pass the
 2GB; the other problem is the ammount of ram, that could not be enough for
 a direct calculation in MP2 (not enough for having results in a reasonable
 time on a medium size sistem with a 6-31G+(d) basis), but the best thing
 to do is trying anyway a direct SCF calculation (keyword SCF(direct)).
 Best reguards
 Alessandro
 Dott. Alessandro Contini
 Istituto di Chimica Organica, Facoltà di Farmacia
 Università degli Studi di Milano
 Via Venezian, 21 20133 Milano
 Tel. +390250314480  Fax +390250314476
 http://users.unimi.it/istchimorg/pagconthtm.htm
 On Tue, 17 Sep 2002, Dario Narducci wrote:
 > Hello to everybody,
 >
 > I'm using Gaussian98 (Linux, 64 MB RAM, more than 2 GB of avail. HD).
 > Trying to compute vibrational spectra using RHF/MP2 (direct) I get the
 > following error message :
 > "Erroneous write during file extend. write 237567 instead of 4096
 Probably
 > out of disk space" after which the job dies.
 >
 > My input file is:
 > %nproc=2
 > %mem=15MW
 > #p MP2/6-31G** FREQ=NoRaman
 >
 > When trying to use instead MP2(Fulldirect) the message changes into
 "Cannot
 > use MP2=Incore or MP2=FullDirect for this calculation."
 >
 > As, when I use this option for an optimization run, it works well, I wonder
 > how I could menage to compute vibrational frequencies with MP2.
 >
 > Any suggestion welcome. Thanks
 >
 >
 >
 >
 >
 >   ================================= oOo ==============================
 >                 Prof. Dario Narducci, Univ. of Milano Bicocca
 >          Dept. of Materials Science, v. R. Cozzi 53, I-20125 Milano
 >      ph. +39-02-6448-5137, fax -5400, mailto:dario.narducci |-at-| unimib.it
 >                       http://www2.mater.unimib.it/narducci/
 >   ================================= oOo ==============================
 >
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