[Wien] linux file size limits & geometry optimisation

[Steven Homolya]

On Sat, 28 Jun 2003, Ma Chi Chiu wrote:

> 1. I always get WIEN97 stopped after LAPW0. The reason stated in dayfiel 
> is "lapw1  -c   (15:43:19) Filesize limit exceeded". Then, I found that  
> the ".vec" file is larger than 2GB (the filesize limit of Redhat linux).  

This is true for ext2 filesystems. Redhat 7.0 or later support ext3, where
the limits are bigger than the size of any hard drive. Could be even
redhat 6.2, I can't remember. Check the redhat docs. I'm pretty sure, the
redhat installation program can convert your ext2 partitions to ext3 w/o
loss of data. But, as always, backup first, just in case.

> 2. If my target is the bandstructure of my molecule but I am not sure the  
> geometry of my molecule. Is it I should perform both "Optimize internal  
> param." and "Optimize Vol. or c/a" ? If it is so, which one should I 
> perform first?
> 

I'd like to know if there is a definite answer to that too. It probably
does not matter. I suppose you'll have to do a series of volume followed
by internal optimisations (or vice versa :-), until the energy is
minimised with respect to both volume and atomic positions.

Steve

-- 
Steven Homolya
School of Physics and Materials Engineering
Monash University, VIC 3800
Australia
Tel: +61 3 9905 3694
Fax: +61 3 9905 3637