Completeness of the exact muffin-tin orbitals: Application to hydrogenated alloys

被引：10

作者：

Al-Zoubi, N. I. ^{[1
,2
]}

Punkkinen, M. P. J. ^{[1
]}

Johansson, B. ^{[1
,3
]}

Vitos, L. ^{[1
,3
,4
]}

机构：

[1] Royal Inst Technol, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden

[2] Tafila Tech Univ, Dept Appl Mat Phys, Tafila, Jordan

[3] Uppsala Univ, Div Mat Theory, Dept Phys & Mat Sci, SE-75121 Uppsala, Sweden

[4] Res Inst Solid State Phys & Opt, H-1525 Budapest, Hungary

来源：

PHYSICAL REVIEW B | 2010年 / 81卷 / 04期

基金：

匈牙利科学研究基金会; 瑞典研究理事会;

关键词：

TOTAL-ENERGY CALCULATIONS; INITIO MOLECULAR-DYNAMICS; SURFACE-ENERGY; GROUND-STATE; ELECTRON-GAS; METALS; PEROVSKITE; SCHEME;

D O I：

10.1103/PhysRevB.81.045122

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We investigate the basis set convergence of the exact muffin-tin orbitals by monitoring the equation of state for Al, Cu, and Rh calculated in the conventional face-centered-cubic lattice (str-I) and in a face-centered-cubic lattice with one atomic and three empty sites per primitive cell (str-II). We demonstrate that three (spd) muffin-tin orbitals are sufficient to describe Al in both structures, but for str-II Cu and Rh at least five (spdfg) orbitals are needed to get converged equilibrium Wigner-Seitz radius (within <= 0.8%) and bulk modulus (<= 3.3%). We ascribe this slow convergence to the nearly spherical densities localized around the Cu and Rh atoms, which create strongly asymmetric charge distributions within the nearest cells around the empty sites. The potential sphere radius dependence of the theoretical results for structure str-II is discussed. It is shown that a properly optimized overlapping muffin-tin potential in combination with the spdfg basis yields acceptable errors in the equilibrium bulk properties. The basis set convergence is also shown on hydrogenated Sc and Sc-based alloys.

引用

页数：10