Electronic Structure of Ordered and Disordered Ternary Intermetallics

1992 ◽  
Vol 291 ◽  
Author(s):  
C. Wolverton ◽  
D. De Fontaine

ABSTRACTA cluster expansion for energetics is combined with a direct, real-space method of studying the electronic structure of ordered and disordered ternary intermetallics. The electronic structure calculations are based on an explicit averaging of local quantities over a small number of randomly chosen configurations. Quantities such as densities of states, one-electron energies, etc., are computed within the framework of the first-principles tight-binding linear muffin-tin orbital method (TB-LMTO). Effective pair interactions, which describe the ordering tendencies of the alloy, are computed for the full ternary alloy. With this technique, then, the effects on ordering trends of ternary additions to a binary alloy may be obtained. Results for Ag-Pd-Rh and Ni-Al-Cu are shown. The self-consistency of these calculations is checked against the fully self-consistent ordered LMTO calculations.

1993 ◽  
Vol 04 (02) ◽  
pp. 417-424
Author(s):  
AXEL SVANE

An ab-initio implementation of self-interaction corrections (SIC) within local spin density (LSD) electronic structure calculations of solids is presented. The linear-muffin-tin orbital method is used in the tight-binding representation and with the atomic spheres approximation. The variational minimum of the SIC-LSD energy functional is found by the steepest descent method, i.e., no matrix diagonalizations are involved. Special care is taken to secure stability with respect to unitarian mixing of electron states. Applied to the transition metal monoxides and La 2 CuO 4 the SIC-LSD significantly improves the desription in comparison to LSD.


1999 ◽  
Vol 13 (04) ◽  
pp. 389-396
Author(s):  
CHIH-KAI YANG

I use a self-consistent electronic structure calculation to study the system of Cu(001) that has an impurity atom replacing one of the surface Cu atoms. The calculation makes use of the tight-binding linear muffin-tin orbitals (TB-LMTO) and is carried out in real space. I am able to derive the spin-polarized local densities of states for the impurity Cr and Fe respectively, which have peaks below the Fermi level. Charge transfers between the impurities and their neighbors also result in different distributions of magnetic moments for the two impurity systems, with the Cr having approximately 0.5μ B and the Fe atom having a negligible magnetic moment.


2015 ◽  
Vol 17 (47) ◽  
pp. 31582-31591 ◽  
Author(s):  
Luigi Genovese ◽  
Thierry Deutsch

Discretizing an analytic function on a uniform real-space grid is often done via a straightforward collocation method.


1995 ◽  
Vol 408 ◽  
Author(s):  
D. J. Sullivan ◽  
E. L. Briggs ◽  
C. J. Brabec ◽  
J. Bernholc

AbstractWe have developed a set of techniques for performing large scale ab initio calculations using multigrid accelerations and a real-space grid as a basis. The multigrid methods permit efficient calculations on ill-conditioned systems with long length scales or high energy cutoffs. We discuss the design of pseudopotentials for real-space grids, and the computation of ionic forces. The technique has been applied to several systems, including an isolated C60 molecule, the wurtzite phase of GaN, a 64-atom cell of GaN with the Ga d-states in valence, and a 443-atom protein. The method has been implemented on both vector and parallel architectures. We also discuss ongoing work on O(N) implementations and solvated biomolecules.


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