I am trying to figure out the difference between the VASP-Gamma version and only using one K point to do DFT simulation. I am working on calculating the DOS and band state of TiO2. My question is: If I need to draw the band structure of a semiconductor, so just like when I do CFD simulation, I ...

When it comes to improving the accuracy of DFT calculations, there is a well known hierarchy: starting from LDA using $E_{xc}[n]$, proceeding with GGA and its $E_{xc}[ n, \nabla n]$ dependency and finally meta-GGAs with $E_{xc}[ n, \nabla n, \nabla^2n~\text{or}~\nabla^2\phi_i]$ I always wonder...