1. The problem statement, all variables and given/known data Hi everyone, I am trying to construct qualitative band diagrams and I think I have confused myself. I am not sure on how to figure out what the electron configurations are of the orbitals when k=0. I get that at k=π/2 it is the opposite state but I can't seem to figure out how to get the initial state. The problem I am working on is an infinite Florine chain at the moment. 2. Relevant equations 3. The attempt at a solution I know it has 4 bands due to it's four orbitals but I can't figure out why at k=0 the 2pz orbital is antibonding. Thanks for the help.