CCL:G: Error in Mp2 calculation

["Close, David M." <CLOSED^mail.etsu.edu>]

This problem comes up on the CCL about once a month.  First you have to tell us what program you are using, and what computer you are using.  Commonly this questions comes up with Gaussian users on 32 bit machines.  I am guessing from your #mp2 keyword line that you are using Gaussian?  If so there are limitations in writing scratch files.  The limitations involve how many addresses the CPU can write.  For example a 32 bit machine can write 16gB unique addresses.  Gaussian typically write these in 2gB files, as described in the manual under rwf.x.  So looking at the available disk space doesn’t help in this case. 

 

From: owner-chemistry(a)ccl.net [mailto:owner-chemistry(a)ccl.net]
Sent: Wednesday, August 20, 2008 5:24 AM
To: Close, David M.
Subject: CCL: Error in Mp2 calculation

 

Dear All,

 

 I was trying to run a MP2/6-31+G* calculation for a system with 232 basis
 functions using the following route card:

 

 

 #mp2(maxdisk=40GB)/6-31+g* fopt freq geom=check guess=read

 

 Before starting the calculation, I checked the disk space and found that 55GB is
 available.

 

 Filesystem           
 Size  Used  Avail Use%    Mounted on

 

 

/dev/mapper/VolGroup00-LogVol00

                            
 73G   14G   55G 
 21%         /

 /dev/sda1  
            99M  
 12M   82M 13%        /boot

 none                 
 247M     0     247M  
 0%         /dev/shm  

 

 

 However, after running the calculation, I got the following message.

 

  **** Warning!!: The largest alpha MO coefficient is 
 0.60503943D+02

 

  Disk-based method using ON**2 memory for 30 occupieds at a time.

 

 

 Estimated scratch disk
 usage=   594240712 words.

  Actual    scratch disk usage=   593732296
 words.

 Erroneous write during file extend. write 28671 instead of 4096

 Probably out of disk space.

 Write error in NtrExt1: Success

 

 

Erroneous write during file extend.
 write 28671 instead of 4096

 Probably out of disk space.

 Write error in
 NtrExt1                   
 

 

 But, when I checked the disk space again, the available space was still
 53GB.

 

 

 I shall be very much obliged if some one can help me out.

 

 Regards,

 

 M. B. Phukan