Dear QE Community, We know that |psi(k,r)> =u(r)exp(ik.r), where u(r) has the periodicity of the lattice. The index k includes band index as well.
I would like to calculate the overlap integral u*_k’(r)u_k(r)d^3r. To this end, I have extracted the real and imaginary parts of wave function coefficients from evc.dat for all the k-points and bands by setting wf_collect=.true.. I have two questions: 1. Am I correct in assuming that the above integral is equivalent to the sum(C*_k C_k’), where C’s are the coefficients from evc.dat and the sum is over igwx (maximum G-vector index) specified in eve.dat? 2. igwx is different for different k-points. One k-point may have igwx=1459 while another k-point has igwx=1468. In the above sum, is it correct to to use the top 1468 coefficients of the first k-point to calculate the overlap integral between the two k-points? An earlier post (http://qe-forge.org/pipermail/pw_forum/2015-April/106663.html) suggests a similar concept for <psi_i|psi_j> but not for <u_i|u_j>. Thank you, Vahid Vahid Askarpour Department of Physics and Atmospheric Science Dalhousie University, Halifax, NS, Canada
_______________________________________________ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
