The ABINIT Users Mailing List ( CLOSED )

[Willy Offermans <Willy@offermans.rompen.nl>]

Dear Marc and Abinit friends,

On Wed, Jul 09, 2008 at 11:02:13AM +0200, TORRENT Marc wrote:
> Dear Willy,
> 
> From my opinon, your results are not suprising.
> 
> 1- The differences on the lenght of the SCF cycle can be explained by 
> the change of the default choice for the mixing scheme (iscf) between 
> the 2 versions.

I agree on that, but this is not the most important difference I would
say.

> 2- The differences on the absolute value of energy can be explained by 
> several bug fixes, especially for spin-polarized systems. But, a 
> difference on the absolute value of the energy does not means that that 
> the physical results are wrong (energy differences may be correct).

The bug fixes could indeed cause the differences. Since performing the
same kind of calculations with N2 does not show this difference.

Generating different output based on equal input is a severe problem
and does not have anything to do with physical results in the first
place. With different I mean differences in total energy _and_
geometry. The O2 bond length is 233 pm, calculated on location B, vs.
122 pm, on location A. It seems that there is no binding anymore in
situation A.

> 
> Also note that a severe bug has been corrected in the computation of the 
> on-site part of the XC energy for spin-polarized GGA calculations (your 
> case here); it it correct from the 5.5 version...

I will install 5.5 version and check!

What 5.5 version should I install? 5.5.4, 5.5.3, 5.5.2 or 5.5.1?

> 
> 
> Marc Torrent
> 
> 
> 
> Willy Offermans (WOffermans) a écrit :
> >Dear Abinit friends,
> >
> >I have found some severe discrepancies in the results of two
> >different abinit versions. At location A I use abinit 5.2.4 on FreeBSD
> >6.2-RELEASE-p7. Abinit has been installed via the ports. At location
> >B I use the version 5.4.4, that is running on 64 bit Linux.
> >
> >The system under inspection is O2, that is calculated with PP and PAW. The
> >results with PP are identical on both locations. Only the PAW
> >results differ.
> >
> >I will include the input files and output files of the PAW calculations.
> >The input is the same at both locations. The output differs severely.
> >
> >I hope someone can have a look and provide some feedback.
> >
> >  
> 

-- 
Met vriendelijke groeten,
With kind regards,
Mit freundlichen Gruessen,
De jrus wah,

Willy

*************************************
Dr. W.K. Offermans
CAT Postdoctoral Fellow
CAT Catalytic Center
Institut für Technische und Makromolekulare Chemie
RWTH Aachen
Worringerweg 1, Raum 38C-150
D-52074 Aachen, Germany
Phone:  +49 241 80 28592
Home:   +31 45 544 49 44
Mobile: +31 653 27 16 23
e-mail: Willy@Offermans.Rompen.nl
e-mail: Willy.Offermans@CatalyticCenter.RWTH-Aachen.de

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