Role of the interatomic interaction in electronic structures. II. Valence-band photoemission

For pt.I see ibid., vol.14, p.2525 (1984). The importance of interatomic interactions in the problem of electron correlation for photoemission is proposed through examinations in the T-matrix approximation. It is found that, for the band narrowing due to the correlation effect, the contribution from the interatomic interaction is comparable with that from the intra-atomic one, while the satellite binding energy is essentially determined only by the strength of the intra-atomic interaction. From the above result it is concluded that the interatomic interaction improves the consistency of the band narrowing and satellite binding energy, which the T-matrix approximation calculation in the Hubbard model cannot. It is also suggested from the calculation for the intensity curve of valence-band XPS that the interatomic interaction may be the main origin of the observed asymmetric distortion of the main curve.