Electronic structure of a Ti(0001) film

A self-consistent calculation of the electronic structure of a thin Ti(0001) film leads to the prediction of a band of surface states coincident with the Fermi level and extending a few tenths of an eV on either side of it. The calculation is performed in a linear combination of Gaussian orbitals basis. The procedure by which the evaluation of the Hamiltonian matrix is reduced to summing over three-center integrals as well as the method by which Gaussian bases are selected are thoroughly described. Observation of the predicted surface band by angle-resolved photoemission is discussed, as well as the question of how general a surface band near the Fermi energy should be among the hcp d-band metals. A shift of surface atom core levels to 0.25 eV greater binding energy is predicted, and the origin of this shift is discussed.