The parameters epsproj and ewind control the amount of basis functions used in the underlying complex bandstructure (CBS) calculation in your case 121; cf. Choi&Ihm (http://journals.aps.org/prb/pdf/10.1103/PhysRevB.59.2267 ) and DalCorso et al. (http://journals.aps.org/prb/abstract/10.1103/PhysRevB.74.045429 ). So one should take a look at the CBS before and check for reasonableness and convergence. Then adapt step by step epsproj and ewind (even more nz1) and check for convergence of the CBS. In your case ewind=2 might be okay, nevertheless I would slightly increase this (3-5). Did you ever tried some meaningful epsproj< 1.d-7, which should be a good value? The number of integral points with 22 seems to be okay. That it worked for other systems could be by accident. Again, as always, one finds the optimal value of the parameters, by checking for convergence of the underlying physics.
bests Nicki ------------------------------------------------------------- Nicki Frank Hinsche, Dr. rer. nat. Institute of physics - Theoretical physics, Martin-Luther-University Halle-Wittenberg, Von-Seckendorff-Platz 1, Room 1.07 D-06120 Halle/Saale, Germany Tel.: ++49 345 5525460 -------------------------------------------------------------
