[gmx-users] 3.3beta vs 3.2 dispersion correction term

[Sukit Leekumjorn]

Thank your for your reply, David

I downloaded the beta version on July 8 2005 from the CVS usage 
website.  I noticed that the heading of the program is in VERSION 
3.3_beta_20050202. I am not certain if this is the latest version. If it 
is not, can you please let me know the patches for the latest version.

Sukit

David wrote:

>On Wed, 2005-07-27 at 16:58 -0400, Sukit Leekumjorn wrote:
>  
>
>>Thank you for your reply, David
>>
>>Sorry about not comparing things one at a time.  I took your suggestion 
>>and tried comparing both cutoff (rvdw=1 and rcoulomb=1.8) and pme 
>>(rvdw=0.9 and rcoulomb=0.9) for both versions without corrections; and 
>>it turns out to be almost exactly the same. I then took an additional 
>>step to compare the pme simulation including the correction factor for 
>>both versions.  Listed below is the total energy caculated in step 0.  
>>You mentioned that the corrction factor in 3.2.1 version is not correct 
>>and it is fixed in the 3.3B version, I am not sure if this is normal for 
>>the correction factor to be 2 orders of magnitude higher, which greatly 
>>effects the total energy of the system.
>>
>>3.2.1 cutoff: -1.71612e+6
>>3.2.1 pme without correction: -1.69195e+6
>>3.2.1 pme with correction: -1.69664e+6 (Disp Corr = -4.69360e+3)
>>
>>3.3B cutoff: -1.71385e+6
>>3.3B pme without correction: -1.69413e+6
>>3.3B pme with correction: -1.96249e+6 (Disp Corr = -2.68357e+5)
>>    
>>
>I get different numbers (step 0 only):
>PME with correction Total energy -1.73585e+06  (Disp corr  -3.54849e+04)
>
>Are you sure you have the latest version? There have been changes in
>this code in april, see:
>http://www.gromacs.org/features/changes33.html
>  
>