[CP2K-user] [CP2K:13001] Electronic Band Structure. K-sampling. Weird behaviour. BN-MoS2-BN

hut... at chem.uzh.ch hut... at chem.uzh.ch
Mon Mar 23 08:17:56 UTC 2020


Hi

the &KPOINTS section defines the kp for the Kohn-Sham calculations.
WAVEFUNCTION REAL is only for very specific usage (and debugging),
please don't use it for normal use.

Once the Kohn-Sham calculation converged, you can calculate the
band structure using a finer grid with the section

    &PRINT
       &BAND_STRUCTURE
          ADDED_MOS 2
          FILE_NAME xx.bs
          &KPOINT_SET
             UNITS  B_VECTOR
             SPECIAL_POINT  Gamma 0.0 0.0 0.0
             SPECIAL_POINT  X     1.0 0.0 0.0
             NPOINTS     10
          &END
       &END BAND_STRUCTURE

This section can be automatically generated using Seek-path

https://www.materialscloud.org/work/tools/seekpath

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: "Sara Fiore" 
Sent by: cp... at googlegroups.com
Date: 03/20/2020 03:17PM
Subject: [CP2K:13001] Electronic Band Structure. K-sampling. Weird behaviour. BN-MoS2-BN

                                         Dear all,  I am experiencing some problems with the band structure calculation 
   1) from the tutorial: https://www.cp2k.org/exercises:2016_uzh_cmest:band_structure_calculation 
   In &KPOINTS section there are 1-A)

 SCHEME MONKHORST-PACK 3 3 1
 why a ‚so small‘ sampling ? Maybe I am misinterpreting it and it does not work in the same way as in QuantumESPRESSO If one wants to compute band structure in QuantumESPRESSO

>From  :   https://www.materialscloud.org/explore/2dstructures/details/3bc1dfdc-6dff-4639-b680-b90ca3d6b342?nodeType=NODE)
- scf :
K_POINTS automatic

 16 16 1 0 0 0


-bands : 132 k points

 1-B) why these settings are different with respect to the default?
WAVEFUNCTIONS REAL 
FULL_GRID .TRUE.

2) my own calculation
My goal would be to compute the band-structure for MoS2 sandwiched 
between two layers of BN : BN-MoS2-BN  I am trying to compute the band structure using the k-sampling. 
attached you find my input/output files.

Bands is the file produced with CP2K

bands.set-1.csv is the file produced by the python script 
attached to the graphene example (see url above)


My problem is that I obtain weird behavior of the bands. 
Specifically, look at the K point the grey and dark green bands. 
They have a very strange behavior (sharp angle)

Can anyone help me understand what I am doing wrong?

Thankyou a lot in advance!

    
  -- 
 You received this message because you are subscribed to the Google Groups "cp2k" group.
 To unsubscribe from this group and stop receiving emails from it, send an email to cp... at googlegroups.com.
 To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/12b3d699-0d80-4389-a371-8fd1290f30d0%40googlegroups.com.
 

[attachment "bands.set-1.csv" removed by Jürg Hutter/at/UZH]
[attachment "MoS2-BN.inp" removed by Jürg Hutter/at/UZH]
[attachment "bands" removed by Jürg Hutter/at/UZH]
[attachment "output" removed by Jürg Hutter/at/UZH]
[attachment "BN-MoS2-BN_zoom.png" removed by Jürg Hutter/at/UZH]
[attachment "BN-MoS2-BN.png" removed by Jürg Hutter/at/UZH]



More information about the CP2K-user mailing list