论文标题
来自相关和自旋轨道计算的新一代有效核心电位:选定的重元素
A new generation of effective core potentials from correlated and spin-orbit calculations: selected heavy elements
论文作者
论文摘要
我们为I,TE,BI,AG,AU,AU,PD,IR,MO和W的元素引入了新的相关性有效核心电位(CCECPS),$ 4D $,$ 5D $,$ 6S $,6S $和$ 6P $ Valence Space。这些CCECP作为平均相对论有效电位(AREP)和有效自旋轨道(SO)项的总和。该构建涉及多个步骤,从更简单到完全相关的方法的改进增加。优化是具有包括加权多体原子光谱,规范保存标准和自旋轨道分裂的目标函数进行的。可转移性测试涉及相应氢化物和氧化物二聚体的分子结合曲线。在所有测试标准上,构造的CCECP在系统上更好,在少数情况下,与以前的有效核心电位(ECP)表相当,并通过这些元素可以显着提高仅价值计算的准确性。我们的研究证实了即使在存在相当大的旋转轨道效应的情况下,也证实了AREP部分在确定ECP的总体质量方面的重要性。随后的量子蒙特卡洛(QMC)计算指出了精确试验波函数的重要性,这些函数在某些情况下(中期过渡元素)需要远远超出单一参考的治疗。
We introduce new correlation consistent effective core potentials (ccECPs) for the elements I, Te, Bi, Ag, Au, Pd, Ir, Mo, and W with $4d$, $5d$, $6s$ and $6p$ valence spaces. These ccECPs are given as a sum of spin-orbit averaged relativistic effective potential (AREP) and effective spin-orbit (SO) terms. The construction involves several steps with increasing refinements from more simple to fully correlated methods. The optimizations are carried out with objective functions that include weighted many-body atomic spectra, norm-conservation criteria, and spin-orbit splittings. Transferability tests involve molecular binding curves of corresponding hydride and oxide dimers. The constructed ccECPs are systematically better and in a few cases on par with previous effective core potential (ECP) tables on all tested criteria and provide a significant increase in accuracy for valence-only calculations with these elements. Our study confirms the importance of the AREP part in determining the overall quality of the ECP even in the presence of sizable spin-orbit effects. The subsequent quantum Monte Carlo (QMC) calculations point out the importance of accurate trial wave functions which in some cases (mid series transition elements) require treatment well beyond single-reference.