CCL:G: G09 Memory



Sent to CCL by: "Emmanuel N. Koukaras" [koukaras/./physics.upatras.gr] Hello,
   you mentioned that you are working with the Windows version of Gaussian 09. The Windows version is a 32bit application. Regardless if you are running it in a 64bit Windows machine the maximum memory that it can theoretically allocate is 2 GB. See for instance: http://www.gaussian.com/g_prod/g09w.htm 
   Practically, I would suggest you use something like:
%mem=1350MB

Hope this helps.

Best wishes to all for the new year,
Emmanuel


On 31/12/2010 11:27 μμ, Shirin Seifert shirin.seifert|gmail.com wrote:
Thanks,
here is the complete error message:
Out-of-memory error in routine OMatEl (IEnd=      33553462 MxCore=      33553432)
 Use %mem=33MW to provide the minimum amount of memory required to complete this step.

The problem is that although I have installed 6GB RAM on my system I can not set more than about 2GB RAM using %Mem or setting it in Default.ROU file using -M-
When I set more than about 2GB memory, the G09 program terminates without any error message in the output file. But the message "Severe Error message #2061 can't lock memory block for additional job list.

I checked the available memory in task manager. More than 5GB memory was available.

Thanks for your help.
Regards,
SS

On Fri, Dec 31, 2010 at 7:54 PM, Jean Jules FIFEN julesfifen{:}gmail.com <owner-chemistry a ccl.net> wrote:
Staying only in the portion of message error you posted, I can say that, you have sufficient memory installed to run this job. However, I am not sure that you have sufficient available memory, since a part of the RAM memory is used by others softwares running or installed in your computer. As you use Windows OS, first try to check the available memory.
The other thing you can do is to send to us the full contains of the errors messages you obtained successively with the first lines of the related inputs.

Best regards,

On 31 December 2010 15:18, Shirin Seifert shirin.seifert,,gmail.com <owner-chemistry][ccl.net> wrote:
Thank you very much Dr. Jules,
When I start a CASSCF calculation using Gaussian 09 I get the message :
use %mem=127MW ....
I have only 6GByte memory installed on my system. I set %mem but still I get a similar error message with different memory requirements .
Gausian 09 is on windows 2003 server (64bit)

Do you know how to solve this problem?

Best regards,
SS


On Fri, Dec 31, 2010 at 4:19 PM, Jean Jules FIFEN julesfifen a gmail.com <owner-chemistry.:.ccl.net> wrote:
%mem set in the input file override the value set in the defaut.route file and tell to the program that, the maximum memory to be used to conduct the related job is the specified value. Of course, the value specified should be less than the physical memory installed in the computer. Program can also use scratch disk when enough memory is not available, depending on the key words specified in the input file. For example (see the section relevant to SCF in the gaussian manual),

SCF=Direct
Requests a direct SCF calculation, in which the two-electron integrals are recomputed as needed. This is the default SCF procedure in Gaussian. This is possible for all available methods, except for MCSCF second derivatives and anything using complex orbitals.

SCF=InCore
Insists that the SCF be performed storing the full integral list in memory. This is done automatically in a direct SCF calculation if sufficient memory is available. SCF=InCore is available to force in-core storage or abort the job if not enough is available. NoInCore prohibits the use of the in-core procedure, for both the SCF and CPHF.

SCF=Conventional
The two-electron integrals are stored on disk and read-in each SCF iteration. NoDirect is a synonym for Conventional.

In gaussian 09, they are new algorithms that make the software to provide state-of-the-art performance in single CPU, multiprocessor/multicore and cluster/network computing environments. So, in gaussian 09, you don't need a large amount of RAM. In this latest version of the software, you could need less than a quater of the memory which was necessary in the later version. 

Best regards,



On 31 December 2010 12:28, Shirin Seifert shirin.seifert[A]gmail.com <owner-chemistry!^!ccl.net> wrote:
Dear CCL members,
Should the memory amount set with %mem be physically installed on the system? or the program uses scratch hard disk when enough memory is not available?
Does gaussian 09 need a large amount of RAM ?

Thank you for your help beforehand.



--
J. Jules.





--
J. Jules.



--
 ================================================================
 Emmanuel N. Koukaras, Ph.D.
 Postdoctoral Research Fellow,
 Computational Condensed Matter Physics and Material Sciences,
 Sector of Theoretical Physics,
 Department of Physics, University of Patras
 Tel: (+30) 2610 997729
 www: http://moleng.physics.upatras.gr/personnel/ENKoukaras.html
 ================================================================