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