Atomic orbitals core energy level

In the solid state the core levels of atoms essentially remain as discrete, localized levels as shown in Figure 5.28. The valence orbitals overlap significantly with those of neighbouring atoms, generating bands of spatially delocalized energy levels. 

Jf(t) which we shall use in this chapter. We must mention, however, that somewhat more complicated forms have been introduced in order to consider some special aspects of the problem. Some of the most notable include that used by Bloss and Hone (which has a core level in the solid and two orbitals on the atom), those which take into account the scattering of atoms with large velocity components parallel to the surface and that recently considered by Kawai et in order to suggest a possible new experimental technique for studying energy levels of atoms in collision with surfaces. 

In conclusion, the energies E that sahsfy Eq. (1.19) are associated to molecular electronic states. Since Eq. (1.19) is an equation of Nat order, we obtain Nat energy values E/ (/ = 1,. .., Nat), that is, as many molecular levels as atomic orbitals. In the simple example of H2 discussed in Sechon 1.1, Aat = 2 and both I5 atomic orbitals combine to form bonding ag and antibonding a MOs. In the case of N2 (see Fig. 1.1), neglechng I5 core electrons, the combinahon of two sp and one pz atomic orbitals per N atom leads to six MOs. 

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