Dear All, I have a question concerning the breaking of time-reversal symmetry within PWscf. For my proposes I have modified the code and included a (periodic) vector potential into the Hamiltonian. The code gives very good results for the quantity that I am interested in for molecules, i.e. gamma-point calculations. However, when I try to do calculations for periodic solids, the results worsen.
I think the code (unless you do spin-orbit coupling) assumes time- reversal symmetry. In principle, including a vector potential breaks time-reversal symmetry. But, in the cases of my gamma-point calculations that did not cause any problems ( psi_(-k)=psi_(k)* for k=gamma ) and hence, I get good results for molecules. However, maybe this is the problem with my calculations for extended systems: including the vector potential breaks time-reversal symmetry, and in general psi_(-k) is not psi_(k)*, but the code is not "aware" that the symmetry has been broken. Thus, my question is: is there a simple way to tell the code that time-reversal symmetry is broken without getting into spin-orbit stuff? Thanks, Timo Thonhauser, MIT ______________________________________________________________________ Dr. TIMO THONHAUSER Department of Materials Science and Engineering (617) 253 6026 MIT, 13-4084, 77 Massachusetts Avenue thonhauser at mit.edu Cambridge, MA 02139-4307, USA www.mit.edu/~thonhaus ______________________________________________________________________
