The basis set convergence of spin-spin coupling constants calculated by density functional methods
The basis set convergence of spin-spin coupling constants calculated by density functional methods
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DOI：
10.1021/ct600166u
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发表时间：
2006-09-12
影响因子：
5.5
通讯作者：
Jensen, Frank
中科院分区：
文献类型：
--
作者：
Jensen, Frank
先前提出的极化一致的基组，优化密度泛函计算，计算间接核自旋-自旋耦合常数进行评估。基组极限值可以通过使用越来越大的基组执行一系列计算来获得，但是通过添加具有大指数的函数可以显着改善收敛性。精确计算费米接触贡献需要增加紧s函数，而顺磁自旋轨道贡献对紧p函数的存在很敏感。自旋偶极贡献需要添加p、d和f函数。紧函数的最佳指数可以通过优化所有自旋-自旋耦合常数贡献的绝对和来获得。在一系列测试用例的基础上，我们提出了一个标准的紧s，p，d和f函数集，以添加到偏振一致的基组。所得到的pcJ-n基组应该适合于用密度泛函方法计算自旋-自旋耦合常数。
The previously proposed polarization-consistent basis sets, optimized for density functional calculations, are evaluated for calculating indirect nuclear spin-spin coupling constants. The basis set limiting values can be obtained by performing a series of calculations with increasingly larger basis sets, but the convergence can be significantly improved by adding functions with large exponents. An accurate calculation of the Fermi-contact contribution requires the addition of tight s functions, while the paramagnetic spin-orbit contribution is sensitive to the presence of tight p functions. The spin-dipolar contribution requires the addition of p, d, and f functions. The optimal exponents for the tight functions can be obtained by optimizing the absolute sum of all contributions to the spin-spin coupling constant. On the basis of a series of test cases, we propose a standard set of tight s, p, d, and f functions to be added to the polarization-consistent basis sets. The resulting pcJ-n basis sets should be suitable for calculating spin-spin coupling constants with density functional methods.