Greetings,
I have a bit of problem in setup the basis set of my DFT study for ZnO.. As you can see in the image attached below, I use B3LYP 6-31G (d,p) for geometrical opt. of ZnO.. But sadly, I still cannot get the energy gap of 3.4 eV for ZnO... At best I can get is 3.6 eV when using B3LYP 6-311G... Can someone make a suggestion on how to improve my calculation to get an accurate energy gap of ZnO using B3LYP.... Thank you !!