Estimation of ΔR/R values by benchmark study of the Mossbauer isomer shifts for Ru, Os complexes using relativistic DFT calculations
Estimation of ΔR/R values by benchmark study of the Mossbauer isomer shifts for Ru, Os complexes using relativistic DFT calculations
复制标题
通过使用相对论 DFT 计算对 Ru、Os 配合物的穆斯堡尔异构体位移进行基准研究来估计 ΔR/R 值
DOI：
10.1007/s10751-017-1413-y
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发表时间：
2017
影响因子：
--
通讯作者：
S. Nakashima
中科院分区：
文献类型：
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作者：
M. Kaneko;H. Yasuhara;S. Miyashita;S. Nakashima
本研究对每十组Ru和Os化合物应用道格拉斯-克罗尔-赫斯（DKH）汉密尔顿的全电子相对论DFT计算。我们采用分段全电子相对论收缩基组（SARC）对三种密度泛函（BP 86，B3 LYP和B2 PLYP）进行了基准研究，得到了99 Ru和189 Os的穆斯堡尔同质异能位移. BP 86层次理论的几何优化将结构定位在局部最小值中。我们用单点计算得到的波函数计算接触密度。所有的泛函都与99 Ru和189 Os的实验异构体位移有很好的线性相关。特别是，B3 LYP泛函与BP 86和B2 PLYP泛函相比给出了更强的相关性。SARC与良调基集（WTBS）的接触密度比较表明，接触密度无法获得数值收敛性，但重现性对基集的选择不太敏感。利用基准结果，我们还估算了99 Ru和189 Os核素的重要核常数ΔR/R值。计算的ΔR/R值的符号与99 Ru和189 Os的预测值一致。在B3 LYP水平上，采用SARC基组，计算得到99 Ru和189 Os（36.2keV）的ΔR/R值分别为2.35×10 - 4和-0.20 ×10 - 4.
The present study applies all-electron relativistic DFT calculation with Douglas-Kroll-Hess (DKH) Hamiltonian to each ten sets of Ru and Os compounds. We perform the benchmark investigation of three density functionals (BP86, B3LYP and B2PLYP) using segmented all-electron relativistically contracted (SARC) basis set with the experimental Mössbauer isomer shifts for99Ru and189Os nuclides. Geometry optimizations at BP86 theory of level locate the structure in a local minimum. We calculate the contact density to the wavefunction obtained by a single point calculation. All functionals show the good linear correlation with experimental isomer shifts for both99Ru and189Os. Especially, B3LYP functional gives a stronger correlation compared to BP86 and B2PLYP functionals. The comparison of contact density between SARC and well-tempered basis set (WTBS) indicated that the numerical convergence of contact density cannot be obtained, but the reproducibility is less sensitive to the choice of basis set. We also estimate the values of ΔR/R, which is an important nuclear constant, for99Ru and189Os nuclides by using the benchmark results. The sign of the calculated ΔR/Rvalues is consistent with the predicted data for99Ru and189Os. We obtain computationally the ΔR/Rvalues of99Ru and189Os (36.2 keV) as 2.35×10−4and −0.20×10−4, respectively, at B3LYP level for SARC basis set.