Hi. please help me. i realy need a quick reply. I study the bandStructure of SrS with and without Spin-orbit but I have no enough information to explanation it. the Sr has([kr] 4s2 4p6 5s2) and S has([Ne] 3s2 3p4) Structure. I attache the bandStructure of this compound calculated using pseudopotential(dot-line is with spin-orbit and solid line without Spin-orbit effect). the lowest band is (4s Sr) the second band is (4p Sr) the , third line is (3s S) and the band below the fermi is (3p s). I have two question? 1.degeneracy in (4p Sr)band is 3-fold or 6-fold? 2. If the degeneracy for 3band of p like is 3-fold, why we have 3-fold degeneracy in [itex]\Gamma[/itex] point but 2-fold in [itex]X[/itex] point in absent of Spin-orbit? I mean in absent of spin-orbit, what effect splits degeneracy(crystal field)? 3. I don't know how use of H=/[2m2C2r] [dV]/[dr] L.S to interpret difference in strong splitting between 4p Sr and 3p S? please i need a quick reply.