The one you are using: ibrav=1. Do not expect to see a band structure similar to the usual one tho
stefano (sent from my phone) > On 31 Oct 2016, at 03:03, evan <[email protected]> wrote: > > Dear Stefano and Andrew > > Thank you for your kind replies. Let me ask a more general question which I > think about. > > I want to calculate the band structure of GaAs (FCC structure) in a simple > cubic lattice cell with eight atoms (ibrav =1). If I specify the k points in > units of 2pi/a (K_POINTS tpiba_b), the high symmetry points in Brillioun zone > of which cell I should specify in the input file, FCC (ibrav =2) or those of > SC (ibrav=1) lattice structure? > > If I specify the k points in in crystal coordinates (K_POINTS crystal_b), > then of which cell I should specify the k points in the input files, FCC or > SC lattice structure. > > Thank you in advance. > > Regards > > Evan > > USC, China > > > At 2016-10-30 02:17:33, "stefano de gironcoli" <[email protected]> wrote: > Dear Evan, > GaAS structure is zincblend (2 atoms per cell). its X point is indeed > 2pi/a(1,0,0). > if you choose to compute GaAs in a SC cell (8 atoms pr cell) then that > point is indeed equivalent to Gamma. The zone boundary of the SC cell is > pi/a(1,0,0) but this of course does not correspond to the X point of the > zincblend structure. > HTH > stefano > >> On 29/10/2016 16:00, evan wrote: >> Hello, everyone >> >> I calculated the band structure of GaAs in a simple cubic lattice cell >> (ibrav=1), I searched from the internet the coordinates of X-point in the >> first Brillouin zone are 2pi/a(0,0,1) or 2pi/a(1,0,0), but both results show >> that band gap occurs at G and X points simultaneously, it seems to me that >> the X is equivalent to G, can you tell me the correct X point coordinates >> which give me the reasonable result. The input files and results are >> attached, you can show what is wrong in the input file. >> >> Your suggestions are appreciated. >> >> Yours sincerely >> >> Evan >> >> USC, China >> >> >> >> >> >> >> >> >> >> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum > > > > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum
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