Dear All, Is any body familiar with the scatter_forw.f90 subroutine of PWCOND? I think there is a bug in this subroutine at the place where you calculate intw2, which is z integration of nonlocal wavefunction with beta function. I have looked up the necessary formulae in the Choi & Ihm's paper (PRB 59, 2267, Jan 1999). In the paper, nonlocal wavefunction has 3 terms, one of which contains beta function, say W. The other two parts dont have any W in them, rather they are just plane wave solution. (Please have a look at equation 24 and 26 of the paper ). So, when we are doing z integration of nonlocal wavefunction with beta function W, we should have three terms, one of which should contain two W, but rest should just have one W. On the other hand in the code all three terms contain two beta functions!! (please have a look at line 228 of scatter_forw.f90). I am wondering if my understanding is right? I have one more question in the later part of the same subroutine. What does the lapack subroutine ZGESV(2*n2d,2*n2d+norb*npol,amat,2*n2d,ipiv,xmat,2*n2d,info) do? I tried to look it up and i got the idea that it is trying to solve amat*x=xmat, with amat and xmat known and x unknown, and at the end of calculation it stores x in xmat. so, basically it does-- x=[(amat)^(-1)]*xmat. Am i right? So, it changes the structure of xmat from what is defined in 'constructs matrices' part. Is it correct? Also, afterwards in this code where it 'rotates integrals' is not very clear to me. Could somebody please tell me in little detail, what is going on here? Also, is this subroutine written just on the basis of Choi and Ihm paper, or are there more reference to it? If yes, would someone mind mentioning them?
Regards, Manoj Srivastava Physics Graduate Student University of Florida, Gainesville,FL, USA