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Coherent potential approximation
About: Coherent potential approximation is a research topic. Over the lifetime, 1930 publications have been published within this topic receiving 36805 citations.
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TL;DR: In this paper, the optical spectrum of crystalline anthracene has been calculated using a cluster Dynamical Coherent Potential Approximation (DCPA) and obtained quantitative agreement with experiments.
1 citations
TL;DR: In this article, the authors studied the role of the crystal field effect and Coulomb interaction between localised and itinerant states as driving mechanisms for the valence transition in a trivalent rare earth-BxS system.
Abstract: The Sm valence transition, similar to the pressure-induced transition in pure SmS, has been observed in a large number of cases by substituting a trivalent rare earth, B, for Sm, thereby forming isostructural alloys with a lattice constant smaller than that of semiconducting SmS. Such substitutions are expected to exert a 'chemical' pressure which simulates the external pressure. However, divalent substitutions (Yb, Eu and Ca), although having a favorable 'size' factor, do not induce any valence transition. Accordingly, band structure effects, essentially due to the relative position of the conduction bands of SmS and BS, should also be taken into consideration. In order to clarify the role which the lattice constant and the electronic structure play in the valence transition, the authors have studied these alloys using the coherent potential approximation (CPA) including both the crystal field effect and the Coulomb interaction between localised and itinerant states as driving mechanisms. For Sm, they consider the 'homogeneous' picture, each Sm site having the average valence; then the Sm1-xBxS system is reduced to a binary alloy. Charge transfer between the f states of Sm and the alloy conduction band (i.e. Sm valence change) is determined self-consistently.
1 citations
TL;DR: In this paper, a general expression for all elements of the orbital magnetic susceptibility tensor of conduction electrons in a disordered system is derived in the one-electron approximation using the Green-function method.
Abstract: A general expression for all elements of the orbital magnetic susceptibility tensor of conduction electrons in a disordered system is derived in the one-electron approximation using the Green-function method. The result is used to calculate the orbital magnetic susceptibility of alloys within the coherent potential approximation by a single-band model and that of dilute impurities and simple liquid metals by the pseudopotential method. Compact expressions for the orbital magnetic susceptibility of these systems are obtained and a numerical result is given for the case of dilute impurities which have a bound state.
1 citations
TL;DR: In this article, nonmagnetic impurities of arbitrary concentration in the periodic Anderson model in infinite dimensions d = ∞ were studied and perturbation theory up to second order in the Coulomb correlation was used together with the coherent potential approximation to treat the impurity scattering.
Abstract: We study nonmagnetic impurities of arbitrary concentration in the periodic Anderson model in infinite dimensions d = ∞. We use perturbation theory up to second order in the Coulomb correlation U to treat the correlation together with the coherent potential approximation to treat the impurity scattering. We calculate the electrical resistivity R ( T ) as a function of temperature for different impurity concentrations and obtain qualitatively the behavior seen experimentally.
1 citations
TL;DR: In this paper, the structural and magnetic properties of Ni2-x Pt x MnGa alloys were investigated from first principles calculations with the help of the spin-polarized relativistic Korringa-Kohn-Rostoker and Plane-Wave Self-Consistent Field methods.
Abstract: Structural and magnetic properties of Ni2-x Pt x MnGa alloys are investigated from first principles calculations with the help of the spin-polarized relativistic Korringa-Kohn-Rostoker and Plane-Wave Self-Consistent Field methods. The atomic chemical disorder at specific site has been implemented using coherent potential approximation. Calculated equilibrium lattice parameters are in a good agreement with experimental data and other theoretical calculations. The composition dependences of the magnetic exchange couplings and the Curie temperature for cubic phase are obtained. Our calculations have shown that an increase content of Pt results to decrease of magnetic interactions between Mn atoms and to change of interaction sign from ferromagnetic type to antiferromagnetic one for composition Ni1.0Pt1.0MnGa. Calculated Curie temperatures are in an agreement with experimental data.
1 citations