EPW Forum

Dear all,
I've calculated el-ph coupling constants of naphthalene by qe-6.4.1 and EPW v.5.1.0. But actually i need the real space (or Wannier space) el-ph coupling constants,so i slightly changed bloch2wan.f90(and the subroutine is ephbloch2wanp). So i get some results as the graph shows:
[img][https://i.loli.net/2020/11/10/bYanpjvD8BwsJxe.png].
[img][https://i.loli.net/2020/11/10/NO1iALaCSfTzug9.png]

And i've already known it was based on Eqn. 24 of PRB 76, 165108 (2007) g(R_e,R_p) = (1/nq) sum_q e^{-iqR_p} g(R_e,q). However,i don't know what the exact meaning of Re and Rp. And what the meaning of 109 and 17 in the second picture, and why it is the same about the number of WS vectors for phonon and electron-phonon.

For example, in 1D molecular chain, Wannier function maybe located on one atom, so the |Re1-Re2| maybe is the distance between two nearest wannier function. |Rp1-Rp2| maybe the distance between two nearest nucleus.But i don't really know about it. I just guess. If anybody knows,please tell me!!! And if there are some graphs to depict it,that will be easy to understand.

Thanks a lot,

Jisheng

Hello,

From my understanding, R_e and R_p basically refer to the unit cells. So if R_e = 2, you're computing the el-ph interaction between WF n in unit cell 2, and WF m in unit cell 0 (everything is defined w.r.t. 0). The papers on EPW should explain it better. I believe for R_e and R_p there should be 3 components, so that you have R_e{x}, R_e{y}, R_e{z}, etc.