[CP2K-user] some questions about periodic calculations

Tahere Kheshti tahere... at gmail.com
Wed Jun 23 12:25:31 UTC 2021

 Dear all

I am interested in studying the structural, electronic, and optical
properties of periodic systems. I used to calculate the gas phase using
Gaussian software. Now for the first time, I want to calculate in
solid-state by cp2k. I have got some basic questions about periodic
calculations. Please forgive me if I am asking very general questions, and
so many....!

I want to start from the crystal X-ray structure...you can see it in the
attached file!

1) Can I replace some of its atoms with arbitrary atoms? for example F atom
instead of H atom... If I can, I must do calculations by cell-opt run
type??? or geo-opt is also good?!

 2) As you see in the attached file, in my x-ray unit cell, there are some
atoms outside of the box.  Should such atoms be deleted before converting
the CIF file to XYZ format? or not?

3) Can this structure be investigated in 2D?

4) If I want to investigate the electronic and optical properties of this
structure, can I use the single unit cell or should it be in the form of a
supercell? Are the properties of the unit cell and supercell different?

5) There is an important physical concept in the solid-state called k
point! Is it necessary to enter its keyword ?! or it is set by default...I
don't know?  Do you think I should enter it in the input file? whether
unit-cell or supercell!

I am very sincerely eager to get an answer? please.

Thanks a lot for helping
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20210623/ed157f00/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: jp0c07268_si_002-2.cif
Type: application/octet-stream
Size: 5434 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20210623/ed157f00/attachment.obj>

More information about the CP2K-user mailing list