Hartree-Fock semiempirical Austin Model

Several quantum-chemical methods with varying degrees of sophistication are used in our theoretical investigations. We usually optimize the geometry of ohgothiophenes by means of the Hartree-Fock semiempirical Austin Model 1 (AMI) [41] or Modified Neglect of Differential Overlap (MNDO) [42] methods, that allow one to deal... 

The systems discussed in this chapter give some examples using different theoretical models for the interpretation of, primarily, UPS valence band data, both for pristine and doped systems as well as for the initial stages of interface formation between metals and conjugated systems. Among the various methods used in the examples are the following semiempirical Hartree-Fock methods such as the Modified Neglect of Diatomic Overlap (MNDO) [31, 32) and Austin Model 1 (AMI) [33] the non-empirical Valence Effective Hamiltonian (VEH) pseudopotential method [3, 34J and ab initio Hartree-Fock techniques. 

SMI [50], SMla [50], SM2 [52], SM2.1 [54], SM2.2 [55], SMS [52,56], and SM3.1 [54] methods were parametrized only for water, and the partial charges for the electrostatic contribution were based on a Mulliken analysis of the semiempirical molecular orbital wave functions, in particular the wave functions obtained by the Austin Model 1 (AMI) [57] and the Parametrized Model 3 (PM3) [58]. These charges, like those calculated from ab initio minimum-basis-set Hartree-Fock calculations, tend to overestimate the charge separations and polarities. Since the errors are systematic, the parametric expressions for surface tensions compensate these errors. 

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