Just recently got into DFT and I've been doing a few calculations on my own on Quantum Espresso. I've come up with electronic band structures for materials that I've been looking at and I was hoping to see if I'm coming up with the right conclusion regarding them. Two of them are shown below (used EV-GGA to calculate for these, could have used others, but I'm sticking to the Engel-Vosko for now)
These are undoped materials, and so I'm seeing that these are metallic in nature. I guess my main question is, what makes the Fermi level pass through the valence or conduction band? Is it the interaction of the orbitals of the atoms in the crystal? And would doping have an effect on the position of the Fermi level in these materials (electron doping in the first case, and hole doping in the second case)?