[CP2K:9910] Problem with Atomic Energies

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

Hi

unfortunately, it is not that easy. Apart from the fact that
breaking up Exc in atomic terms is arbitrary, there is no obvious way
to do it in CP2K as Exc is calculated on a uniform grid.
qs_vxc_create in qs_vxc.F is the high level routine that calculates Exc.

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: cp2k <cp... at googlegroups.com>
From: yufeng.ch... at gmail.com
Sent by: cp... at googlegroups.com
Date: 01/24/2018 07:51PM
Subject: Re: [CP2K:9910] Problem with Atomic Energies

Hi Juerg,

Thank you for the explanation. It is interesting that atomic energy decomposition can be performed for HF, but not DFT, since DFT is not much different, and the Exc integration w.r.t. individual atoms seems quite trivial. Just curious if you know of any plan to include the XC term in the future for these sorts of energy decomposition analyses? If not, since CP2K is open source, I wonder where to start in the source code if I were to implement this for my own use. 

Thanks so much.

On Wednesday, January 24, 2018 at 1:46:19 AM UTC-8, jgh wrote:Hi 
 
yes, you are right, the code stops because of the difference 
in the total energy and the sum of atomic energies. 
The cause of the error is that one term (Exc) has not been 
implemented. Atomic energies only works for (some) classical force fields, 
semi-empirical methods, and HF. 
 
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: yufeng... at gmail.com 
Sent by: cp... at googlegroups.com 
Date: 01/24/2018 05:58AM 
Subject: [CP2K:9901] Problem with Atomic Energies 
 
Hi, 
 
I am trying to calculate the atomic energies using the following properties keywords: 
 
  &PROPERTIES 
     &ATOMIC 
     ENERGY 
     &END ATOMIC 
  &END PROPERTIES 
 
within the FORCE_EVAL section. In the output file, the energies were printed, but immediately after that it showed an error: 
 
 ******************************************************************************* 
 *   ___                                                                       * 
 *  /   \                                                                      * 
 * [ABORT]                                                                     * 
 *  \___/                             CPASSERT failed                          * 
 *    |                                                                        * 
 *  O/|                                                                        * 
 * /| |                                                                        * 
 * / \                                                 force_env_methods.F:387 * 
 ******************************************************************************* 
 
I have tried two systems, an SCF calculation of bulk Si with 8 atoms and a geometry relaxation of H2O molecule, both of which were copied from the 2016 cp2k summer exercises, in multiple versions of CP2K, 2.6, 4.1 and 5.1, and on multiple machines, and the problem remained.  
 
In both systems, the atomic energies did not sum up to the total potential energies, for example, the following lines were printed right before the above error message: 
 Potential energy (Atomic):                                    -15.7645860649792 
 Potential energy (Total) :                                    -17.2639239214133 
 Difference               :                                      1.4993378564341 
 
I suspect that there was some cross checking within the program that found the discrepancies and stopped the program from proceeding.  
 
My question is, what should I do with CP2K to obtain these atomic energies? I am still quite new to CP2K and would really want to get this problem solved.  
 
Thanks.   
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