Dear L,
I understand what you're writing that DFPT allows you to simulate a
monochromatic perturbation of any periodicity with a unit cell (learned from
the tutorial), but for frozen phonon, I have no idea yet and need to study more
about its basics.
For short, does it mean for DFPT→1 unit cell is ok, and
frozen phonon→need supercell?
Sorry but for 1 more naive question, if I use 2 unit cell instead of 1 in
DFPT, would it be expected to have difference between the two cases ( only at
Gamma point) ?
Best Regards,
HY Lu
在 2023年11月15日 星期三 下午03:56:04 [GMT+8]， Lorenzo
Paulatto<lorenzo.paula...@cnrs.fr> 寫道：
_______________________________________________
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list users@lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
On 15/11/2023 08:45, ludwigboltzmann.s...@nycu.edu.tw wrote:
Hope this will give you an idea why such symmetry reduced supercell
calculation is being carried out.
The idea is "symmetry reduced".
I.e. DFPT allows you to simulate a monochromatic perturbation of any
periodicity with a unit cell, while frozen phonon can only simulate
perturbation which have the periodicity of the cell you are using. But to break
symmetry, you need a supercell.
kind regards
L
_______________________________________________
The Quantum ESPRESSO community stands by the Ukrainian
people and expresses its concerns about the devastating
effects that the Russian military offensive has on their
country and on the free and peaceful scientific, cultural,
and economic cooperation amongst peoples
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list users@lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
