[CP2K:7734] problems with periodic MP2

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

Hi

I would start by tightening some of the cutoffs:

EPS_SCHWARZ use at least the default value of 1.e-10, maybe even tighter.
EPS_DEFAULT use 1.e-12 or even 1.e-14 if necessary.

Start from a DFT density and use SCREEN_ON_INITIAL_P.

Try to get the HF calculation first, don't do the MP2.
Only use a small number of steps.

regards

Juerg
--------------------------------------------------------------
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: cp2k <cp... at googlegroups.com>
From: katarína stančiaková 
Sent by: cp... at googlegroups.com
Date: 05/11/2016 08:22AM
Subject: [CP2K:7734] problems with periodic MP2

Dear CP2K users,
I am trying to do a single point calculations of a zeolite system using MP2. However, after 300 steps SCF run did not converge (which itself I do not consider as a problem), but the total energies does not seem right for me.  They are in order of magnitude 10 000 a.u. and the fluctuations between iteration steps are of the same magnitude. I expect the total energy of the system to be around 450 a.u., which is a way lower as those numbers. As I have no experience with MP2, I have not a very much idea what can be wrong with my setup, or, if this kind of behavior is normal for MP2. I did the same calculation, but with the water molecule in the given unit cell, and there everything seems to be ok.

I have attached the input and output file.

Thank you for any comments!
Katarina




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[attachment "MP2.relax.Si.inp" removed by Jürg Hutter/at/UZH]
[attachment "MP2.relax.Si.out" removed by Jürg Hutter/at/UZH]
[attachment "PBE_final.relax.Si.xyz" removed by Jürg Hutter/at/UZH]