Re: [Wien] Plasma frequency in semi-metal case and effect of band folding on optical properties

I thought your material has a gap, and the question was only direct or indirect .. ?? Of course, a supercell MUST not change the optical property. The momentum matrix elements should take care that there is no transition from Gamma - "backfolded-X" point. Am 12.07.2013 22:25, schrieb venkate

Re: [Wien] extrnal magnetic field effect

You are absolutely correct, also the magnetic field breaks periodic symmetry. In addition, it is even much MORE complicated than an electric field, because it is gauge-dependent, (origin) The magnetic field acts an both, the spins (via Vxc up/dn, and this is included correctly), and on th

Re: [Wien] Plasma frequency in semi-metal case and effect of band folding on optical properties

Dear sir, *I thought your material has a gap, and the question was only direct or indirect .. ??* If i did the calculations using the structure stimulated from the space group (225), it shows a negative indirect band gap in the band structure (negative indirect band gap means, the valance band ma