The Shockley surface states of electrons in the Kronig-Penney model of a linear chain of atoms joined by alternately strong bonds

The allowed energies of the bond states of electrons in a one-dimensional potential, which is constant along the lines joining the atoms in a chain and has the form of the Diracδ-function in the neighbourhood of the atom, were calculated. The lengths of the bonds alternate. It is found that we get Shockley surface states in a semi-infinite chain, produced from an infinite chain by interrupting the shorter bond. This proves that the results for the given model are qualitatively in agreement with the conclusions reached by the MO LCAO method for an analogical model.