Dear PWSCF mailing list members, I am a novice user of this code, and i intend to do some band structure calculations on a metallic O-terminated polar wurtzite ZnO surface, represented with a periodically repeated H-doped hexagonal slab. I have found a nice tutorial on the band structure calculation of bulk Si: http://people.sissa.it/~degironc/QE-Tutorial/tutorial_pwscf_ex.pdf http://people.sissa.it/~degironc/QE-Tutorial/examples_pwscf_ex.tgz
Although i have followed the instructions in the tutorial very carefully, once i try to plot the band structure with the plotband.x it is clear that the minimum/maximum energy values and the Fermi energy is different (with more than an eV) compared with the values presented in this tutorial. Beside this problem the band structure also shows a feature in the Sigma to Gamma point path not present in the tutorial's plot. I'm just wonderind where this discrepancy is coming from. Did i miscompile the code, or eventually the tutorial was done by mistake with different settings/pseudopotential? Because i have a metallic system, besides the cutoff i should converge with respect to degauss/smearing as well. On which quantities should i keep my eye on, when i try to converge with the degauss/smearing? Is there eventually a preferred smearing scheme which is easier to converge/handle? Is there a sample k-point path implemented in the code? (i would like to have a k-point path along the Gamma to M, M to K, K to Gamma high symmetry points). In what extent will be affected the band structure by the smearing scheme if eventually the system changes from the metallic state to a semiconductor by some adsorbates/surface defects? Also some other usefull hints/tricks/explanations on what to do or not to do in a band structure calculation with PWSCF would be greatly appreciated. I apologize if these questions are obsolete/redundant, but i could not find a straightforward way to search trough the whole content of the mailing list. Best regards, Janos. ================================================================== Janos Kiss e-mail: janos.kiss at theochem.ruhr-uni-bochum.de Lehrstuhl fuer Theoretische Chemie Phone: +49 (0)234/32-26485 NC 03/297 +49 (0)234 32 26754 Ruhr-Universitaet Bochum Fax: +49 (0)234/32-14045 D-44780 Bochum http://www.theochem.ruhr-uni-bochum.de ==================================================================
