[CP2K-user] [CP2K:12504] space group

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

Hi

Unfortunately, I am not familiar with this part of the code.
I would have to read the routines and try to reproduce the
algorithms used. Currently, you know more than I do.
If I find time I will have a look, but I cannot promise.

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: "Pierre-André Cazade" 
Sent by: cp... at googlegroups.com
Date: 11/18/2019 12:42PM
Subject: Re: [CP2K:12504] space group

Dear Juerg,

I have been working in implementing the space group symmetry but I am a bit confused by the content of the x0 and g vectors as found in the subroutine geoopt_bfgs in the file bfgs_optimizer.F. From the various calls and manipulation of these vectors, I get they contained the 3*NATOM coordinates/forces of the system. Furthermore, they can contain the coordinates/forces for shells. There are also extra content which I assume are the unit cell parameters and the associated gradient. However, it is unclear where this extra information is located. From the various part of the code I read, I am under the impression that the cell gradient is located at the end of the g vector while the cell parameters are at the beginning of the x0 vector. I know this to be wrong due to various prints I have made and from how geoopt_bfgs works. Yet pieces of code like the one that follows (found in gopt_f77_methods.F) do not help making it clear:

IF (master == para_env%mepos) THEN ! we are on the master
               CPASSERT(ASSOCIATED(gradient))
               nparticle = force_env_get_nparticle(gopt_env%force_env)
               nsize = 3*nparticle
               CPASSERT((SIZE(gradient) == nsize+6))
               CALL pack_subsys_particles(subsys=subsys, f=gradient(1:nsize), fscale=-1.0_dp)
               CALL apply_cell_change(gopt_env, cell, gradient, update_forces=.TRUE.)
               cell_gradient => gradient(nsize+1:nsize+6)

Would you have a summary of what to find each of these arrays depending on the type of calculation/options requested?

Many thanks,
Pierre


On Friday, November 8, 2019 at 8:31:32 AM UTC, jgh wrote:Hi 
 
point group / space group constraints are not possible. 
 
regards 
 
Juerg Hutter 
-------------------------------------------------------------- 
Juerg Hutter                         Phone : ++41 44 635 4491 
Institut für Chemie C                FAX   : ++41 44 635 6838 
Universität Zürich                   E-mail: h... at chem.uzh.ch 
Winterthurerstrasse 190 
CH-8057 Zürich, Switzerland 
--------------------------------------------------------------- 
 
-----c... at googlegroups.com wrote: ----- 
To: "cp2k" <c... at googlegroups.com> 
From: "Pierre-André Cazade"  
Sent by: c... at googlegroups.com 
Date: 11/07/2019 05:35PM 
Subject: [CP2K:12477] space group 
 
Dear users, 
 
Is there a way to conserve/constraint the space group of crystal when performing a CELL_OPT in the same way we can constraint the lattice system with the keywords KEEP_SYMMETRY  and KEEP_ANGLES? 
 
Many thanks, 
Pierre   
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