Accuracy of Real Space Cluster Expansion for Total Energies of Pd-rich PdX (X=Rh, Ru) Alloys, based on Full-Potential KKR Calculations for Perfect and Impurity Systems
Accuracy of Real Space Cluster Expansion for Total Energies of Pd-rich PdX (X=Rh, Ru) Alloys, based on Full-Potential KKR Calculations for Perfect and Impurity Systems
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基于完美系统和杂质系统的全势 KKR 计算，富 PdX (X=Rh, Ru) 合金总能量的实空间团簇展开精度
DOI：
10.1051/matecconf/201926403002
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发表时间：
2019
影响因子：
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通讯作者：
Mohri Tetsuo
中科院分区：
文献类型：
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作者：
Asato Mitsuhiro;Liu Chang;Fujima Nobuhisa;Hoshino Toshiharu;Chen Ying;Mohri Tetsuo
研究了用于研究富Pd PdX（X=Ru，Rh）合金相稳定性和相平衡的真实的空间团簇展开（RSCE）方法的精度和收敛性.在本RSCE中，微量元素的X原子被视为Pd中的杂质。本文采用全势Korringa-Kohn-Rostoker（FPKKR）绿色函数方法（FPKKR），从低体到高体连续唯一地确定了Pd中X杂质间的三体相互作用能（IE），用于富Pd PdX合金的总能量展开（Pd-host和Xnin Pd，n=1~4），结合密度泛函理论中的广义梯度近似，对Pd的量子化学性质进行了研究。在前一篇文章中，我们证明了RSCE，其中由于Xn杂质插入Pd而引起的扰动势自洽地重新确定到Xn杂质周围的第一最近邻（nn）宿主原子，重现性相当好（误差约为0.2mRy/原子）L12结构有序Pd_3Rh合金的FPKKR能带计算结果，而对于L12结构的有序Pd_3Ru合金，则有一定的误差（~ 0.7mRy/原子）。在本文中，我们表明，这个小的RSCE的Pd_3Ru合金的误差被校正得很好（从~ 0.7mRy ~ 0.1mRy每个原子），通过扩大的自洽区域的扰动电位的2nd-nn周围的Pd中的运行杂质的主原子。我们还阐明了对n体（n=1~ 4）积分方程各值的修正。
We study the accuracy and convergence of the real space cluster expansion (RSCE) for the total energies of the Pd-rich PdX (X=Ru, Rh) alloys, which are used to study the phase stability and phase equilibria of the Pd-rich PdX alloys. In the present RSCE, the X atoms of minor element are treated as impurities in Pd. Then-body interaction energies (IEs) among X impurities in Pd, being used in the expansion of the total energies of the Pd-rich PdX alloys, are determined uniquely and successively from the low body to high body, by the full-potential Korringa-Kohn-Rostoker (FPKKR) Green's function method (FPKKR) for the perfect and impurity systems (Pd-host and Xnin Pd,n=1~4), combined with the generalized gradient approximation in the density functional theory. In the previous paper, we showed that the RSCE, in which the perturbed potentials due to the insertion of Xnimpurities in Pd were redetermined self-consistently up to the first-nearest neighboring (nn) host atoms around Xnimpurities, reproduce fairly well (the error of ~ 0.2mRy per atom) the FPKKR-band-calculation result of the ordered Pd3Rh alloy in L12structure, but a little wrongly (the error of ~ 0.7mRy per atom) for the ordered Pd3Ru alloy in L12structure. In the present paper, we show that this small RSCE error for the Pd3Ru alloy is corrected very well (from ~ 0.7mRy to ~ 0.1mRy per atom) by enlarging the self-consistent region for the perturbed potentials up to the 2nd-nn host atoms around Run impurities in Pd. We also clarify the correction for each value of the n-body (n=1~ 4) IEs.