Discrete variational methods first-principles calculations

The electronic state calculation by discrete variational (DV) Xa molecular orbital method is introduced to demonstrate the usefulness for theoretical analysis of electron and x-ray spectroscopies, as well as electron energy loss spectroscopy. For the evaluation of peak energy. Slater s transition state calculation is very efficient to include the orbital relaxation effect. The effects of spin polarization and of relativity are argued and are shown to be important in some cases. For the estimation of peak intensity, the first-principles calculation of dipole transition probability can easily be performed by the use of DV numerical integration scheme, to provide very good correspondence with experiment. The total density of states (DOS) or partial DOS is also useful for a rough estimation of the peak intensity. In addition, it is necessary lo use the realistic model cluster for the quantitative analysis. The... 

The electronic structures of a series of models were calculated using the first-principles discrete variational-Xa (DV-Xa) molecular orbital (MO) method with a... 

In order to comprehensively show the chemical dissociation process of CO on metal surfaces, electronic structure calculations have been performed for simple models. We have chosen two methods for the present analyses. The first method is the Discrete Variational Xa (DV-Xa) method, which is the first-principles molecular orbital calculation using Slater s Xa fimctional for the electron many body term [21]. This method is applied for the electronic structural analyses of CO adsorption on metal surfaces. The second method is the Full-Potential Linear Muffin-Tin Orbital (FP-LMTO) method, which is the first-principles band structure calculation method [22]. The FP-LMTO implementation code of LmtART [23, 24] is used for the calculations of the density of states (DOS) of non-magnetic fee iron phase. We discuss the electronic structure of transition metal alloys from the rigid band analyses using this DOS. The local density approximation (LDA) parameterized by Vosko et al. [25] is used for the present FP-LMTO calculations. The tetrahedron... 

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