An extension of the discrete variational method to nonuniform grids

Employing the first principles discrete variational method(DVM), we investigated the electronic structure of LaNi5 hydrogen storage alloys containing various alloying elements, M=Mn,Fe,Co. The results showed that s electrons of H mainly interact with s electrons of hydride-non-forming element Ni, though hydride forming element La have stronger affinity to hydrogen atom. And alloying elements strengthened the bond between B-H, so decreased the capacity of doped-system.

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Electronic Structure Analysis for the Effect of Hf, Zr Addition on the Ms of TiNi Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.1921 ◽

2005 ◽

Vol 475-479 ◽

pp. 1921-1924

Author(s):

Lin Cui ◽

Xiao Dong Wang ◽

Min Qi ◽

Da Zhi Yang

Keyword(s):

Electronic Structure ◽

Variational Method ◽

Transformation Temperature ◽

Martensite Transformation ◽

Cluster Model ◽

Bond Order ◽

Tini Alloy ◽

Zr Addition ◽

Discrete Variational Method ◽

Contour Plots

By using the discrete variational method and constructing cluster model, the effect of a few Hf、Zr addition on martensite transformation temperature of TiNi alloy was investigated in electronic level. It is found that the bond order of the strongest bond in the clusters is promoted by introducing the Hf、Zr atoms and the magnitude of bond order is ascendant with increasing number of Hf、Zr atoms in the cluster. At the same time, contour plots of valence charge density on the parent (110) plane show the variety on bond. The change of martensite transformation temperature of TiNi alloy with Hf、Zr concentrations can be reflected by the value of the density of states at the Fermi level for the (110) crystal plane.

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Reliable Estimates of Quasi-Particle Energies and Exci-Tonic Effects in Clusters Through Discrete-Variational-Method Total Energy Calculations

MRS Proceedings ◽

10.1557/proc-491-191 ◽

1997 ◽

Vol 491 ◽

Author(s):

Giancarlo Cappellini ◽

Francesco Casula ◽

Friedhelm Bechstedt

Keyword(s):

Variational Method ◽

Transition Energy ◽

Theoretical Data ◽

Computational Effort ◽

Quasi Particle ◽

Self Energy ◽

Discrete Variational Method ◽

Excitonic Transition ◽

Total Energies ◽

Homo Lumo

ABSTRACTSelf-energy corrections to the DFT-LDA HOMO-LUMO gap for clusters have been calculated through an efficient method based on ΔSCF theory. Total energies for the clusters are obtained via discrete variational method (DVM). Good results in comparison with experiments and available theoretical data for the sodium tetramer Na4 and C60 have been obtained. The localization properties of DVM basis-functions play a fundamental role in obtaining the above results with a strongly reduced computational effort in comparison with ab-initio schemes. For the two systems under study an estimate of the first excitonic transition energy is also given.

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