Dear Siesta users, I have a problem that I wasn't able to overcome despite it has been largely discussed in this mailing list. The following BandLines block is from the input file that have been given to me by Prof. Felix Yudarin:
LatticeConstant 1.98 Ang %block LatticeVectors 2.828427 0.000000 0.000000 0.000000 2.828427 0.000000 0.000000 0.000000 4.3387217 %endblock LatticeVectors %block BandLines 1 0.35355 0.000000 0.000000 X 100 0.00000 0.000000 0.000000 \Gamma 100 0.35355 0.353550 0.000000 M 100 0.35355 0.000000 0.000000 X 100 0.00000 0.000000 0.000000 \Gamma 100 0.00000 0.000000 0.230809 R %endblock BandLines I can't figure out the calculation leading to 0.35355 for X and M point in brillouin zone (and or course 0.230809 for R) . Here's how I calculate that value: X is [2*(pi)/a, 0, 0], where a=2.828427*LatticeConstant is real lattice constant. Thus I'm expecting 2/2.828427 = 0.70710 to be the value I should put in BandLines block. The 0.35355 value is instead about half my value. (first brillouin zone can be found here: http://journals.iucr.org/b/issues/2010/01/00/gw5003/gw5003fig1.jpg) What am I missing? Before concluding this email I want to thank all the people contributing to this mailing list: I couldn't get much far if it hadn't been for all the detailed explanation given here. Best regards, Pietro
