Hello all, I am hoping that someone on this forum might have a bit of chemistry under their belt to lend a hand. I am having trouble with the concept of molecular orbitals. I understand that atomic orbitals form them and there is a conservation of orbitals but I don't understand the physical nature of anti-bonding molecular orbitals. My prof is telling me to think about wave interference, but it doesn't really put a nice 3-D orbital picture in my head. I know how waves function, but I don't see the relation to orbitals. Another thing that is confusing me, is why in the molecular bonding diagram for O2 the 2pi and 2sigma differ in relative energy levels with orientation of the corresponding antibonding 2pi* and 2sigma*. Thanks a bunch!