[CP2K:5400] BLYP Geometry Optimization Problem for CO2-H2O dimer

[hut... at chem.uzh.ch]

Hi

this is most likely related to a numerical instability of the BLYP
functional. Together with the GTH pseudopotentials and a rather
low cutoff, this can cause some problems for MD and geometry optimizations.
I think this was discussed (or mentioned) here before.

You can use either NLCC pseudopotentials, the GAPW method, a considerably
higher cutoff, or a density smearing and interpolation to avoid these
problems.

regards

Juerg Hutter
 
--------------------------------------------------------------
Juerg Hutter                         Phone : ++41 44 635 4491
Institut für Chemie C                FAX   : ++41 44 635 6838
Universität Zürich                   E-mail: hut... at chem.uzh.ch
Winterthurerstrasse 190
CH-8057 Zürich, Switzerland
---------------------------------------------------------------

-----cp... at googlegroups.com wrote: -----
To: cp... at googlegroups.com
From: Hang Xiao 
Sent by: cp... at googlegroups.com
Date: 06/13/2014 05:07AM
Subject: [CP2K:5400] BLYP Geometry Optimization Problem for CO2-H2O dimer

Hi, guys,

When I examine the result of a simple geo_opt job with BLYP functional, I find a weird problem that the result is not even symmetrical when it should be. 

The system is a CO2-H2O dimer in a 15*15*15 Angstrom periodic box, which is a very simple one. I don't know why the result can be so obviously erroneous. After some tests, I find that using PBE instead of BLYP can solve the problem. Also, set CENTER_COORDINATES as true can also do the trick. 

So the problem is with BLYP functional, I couldn't get reasonable result out of this pretty simple system. The input file and trajectory file obtained with CP2K 2.6 are in attachment. 

Any suggestions are welcome. Thank you.

Best,

Hang  
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[attachment "CO2H2O.cp2k" removed by Jürg Hutter/at/UZH]
[attachment "CO2H2O-pos-1.xyz" removed by Jürg Hutter/at/UZH]