[Pw_forum] Electron-phonon coupling code
On Tue, 2014-09-23 at 15:08 -0400, Sridhar Sadasivam wrote: > What does the case electron_phonon = 'Wannier' correspond to? > I see from phonon.f90 that the code would call > ep_matrix_element_wannier.f90 if elph_mat = .true. but this does not > seem to be explained anywhere in the documentation > ( > http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PH.html#idp74656 you may safely assume that what is not explained in the documentation - doesn't exist, or - doesn't work, or - it is not suppported: use at your own risk (more than the rest of the code, I mean) In the specific case, I think that only parts of the code have been released and that there are some parts that are still missing. > Where exactly is there a difference between these two cases? a few lines after those you have listed. P. -- Paolo Giannozzi, Dept. Chemistry, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
[Pw_forum] Electron-phonon coupling code
Dear espresso users and developers, I am trying to read through the electron-phonon coupling code and have a few questions. 1. From phq_readin.f90 SELECT CASE( trim( electron_phonon ) ) CASE( 'simple' ) elph=.true. elph_mat=.false. elph_simple=.true. CASE( 'Wannier' ) elph=.true. elph_mat=.true. elph_simple=.false. auxdvscf=trim(fildvscf) CASE( 'interpolated' ) elph=.true. elph_mat=.false. elph_simple=.false. CASE DEFAULT elph=.false. elph_mat=.false. elph_simple=.false. END SELECT What does the case electron_phonon = 'Wannier' correspond to? I see from phonon.f90 that the code would call ep_matrix_element_wannier.f90 if elph_mat = .true. but this does not seem to be explained anywhere in the documentation ( http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PH.html#idp74656 )? Is this similar to an external program EPW which performs Wannier interpolation from coarse to fine k-point grids. 2. From phonon.f90 IF ( elph_mat ) then call ep_matrix_element_wannier() ELSE CALL elphon() END IF elph_mat = .false. for both electron_phonon = 'simple' and electron_phonon = 'interpolated'. So I guess elphon.f90 is invoked in both simple and interpolated cases. Also in elphon.f90, there is no mention of the variable 'elph_simple'. It looks to me that both simple and interpolated cases would lead to the same code being run. Where exactly is there a difference between these two cases? Thanks so much in advance! Sridhar Graduate Student Purdue University -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140923/e548f0e9/attachment.html
