Question for transport property calculations from EPW summer school
Posted: Mon Aug 07, 2023 4:24 pm
Hi users and developers,
I was participant of 2023 virtual school on many body calculations using EPW and BerkeleyGW. Unfortunately I had issue with HPC for the entire week and could not do hands on session. I am following pdf by Ponce and Leveillee for transport properties. I am trying to compute transport properties of HfTe5. I have few questions regarding making a proper input files.
1) How does one decide the value of fsthick?
2) What is the procedure for calculating Magnetoresistance?
3) There is a flag, bfieldx, bfieldy etc for applying magnetic field. I will be comparing the results in high field experiments up to 60 T. Does it break any approximation if I use large number such as 30-60 T in that flag?
4) I see a flag efermi_read=.true. and fermi_energy=xxx eV in epw2.in. In semiconductor, what value should one write for fermi_energy? Is it valence band maximum or vbm+cbm/2 or anything between vbm and cbm?
5) I saw a flag, lpolar=.true. How does one know if the material is polar? Can we get information on this without any further calculations?
6) For resistivity calculations, do we have to use flag assume_metal=.true. regardless the material has small gap? In the exercise, Pb was used which is a metal but I am wondering about semimetal or semiconductor.
Thank you
Best
Rijan
I was participant of 2023 virtual school on many body calculations using EPW and BerkeleyGW. Unfortunately I had issue with HPC for the entire week and could not do hands on session. I am following pdf by Ponce and Leveillee for transport properties. I am trying to compute transport properties of HfTe5. I have few questions regarding making a proper input files.
1) How does one decide the value of fsthick?
2) What is the procedure for calculating Magnetoresistance?
3) There is a flag, bfieldx, bfieldy etc for applying magnetic field. I will be comparing the results in high field experiments up to 60 T. Does it break any approximation if I use large number such as 30-60 T in that flag?
4) I see a flag efermi_read=.true. and fermi_energy=xxx eV in epw2.in. In semiconductor, what value should one write for fermi_energy? Is it valence band maximum or vbm+cbm/2 or anything between vbm and cbm?
5) I saw a flag, lpolar=.true. How does one know if the material is polar? Can we get information on this without any further calculations?
6) For resistivity calculations, do we have to use flag assume_metal=.true. regardless the material has small gap? In the exercise, Pb was used which is a metal but I am wondering about semimetal or semiconductor.
Thank you
Best
Rijan