Improved electronic properties from third-order SCC-DFTB with cost efficient post-SCF extensions.
Improved electronic properties from third-order SCC-DFTB with cost efficient post-SCF extensions.
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通过具有成本效益的后 SCF 扩展，改善了三阶 SCC-DFTB 的电子特性
DOI：
10.1021/jp307264f
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Elstner
中科院分区：
文献类型：
--
作者：
Kaminski S.M. Gaus;Elstner
目前的工作概述了两个成本有效的后scf扩展到三阶SCC-DFTB代码的实现和性能。第一个是电荷模型3 (CM3)，与标准的Mulliken分配方案相比，它修正了键偶极子中的错误，从而改进了分子电荷分布的描述。第二个重点关注电荷密度的响应，即电子分子极化率，由于使用最小原子轨道基，SCC-DFTB描述的不准确。本文采用了一种基于尺度偶极积分的变分方法，其极化率计算明显优于标准有限电场方法，提高了约1个数量级。本工作中的两个扩展都依赖于一组经验参数，这些参数与112个有机分子进行拟合，以匹配来自全密度泛函计算的参考数据集。作为一项成就，SCC-DFTB计算显著改善了电子性质，即分子偶极矩和极化率，而额外的计算成本可以忽略不计。此外，红外和拉曼强度作为新偶极子的一阶导数和极化率作为正模振动的函数进行了精度测试。因此，与从头开始的参考数据相比，目前的实现无法改进SCC-DFTB相对强度模式的预测。
The present work outlines the implementation and performance of two cost efficient post-SCF extensions into the third-order SCC-DFTB code. The first one, the charge model 3 (CM3), corrects for errors in bond dipoles for an improved description of molecular charge distribution as compared to the standard Mulliken partitioning scheme. The second one focuses on the response of the charge density, that is, the electronic molecular polarizability, described inaccurately from SCC-DFTB due to the usage of a minimal atomic orbital basis. Here, a variational approach, based on scaled dipole integrals, was implemented, which clearly outperforms standard finite electric field approaches for polarizability calculations by approximately 1 order of magnitude. Both extensions in the present work rely on a set of empirical parameters, which were fitted against 112 organic molecules to match a reference data set from full density functional calculations with a large basis. As an achievement, notably improved electronic properties, that is, molecular dipole moments and polarizabilities, result from SCC-DFTB calculations at negligible additional computational cost. Furthermore, the accuracy of infrared and Raman intensities was tested as first-order derivatives of the new dipoles and polarizabilities as a function of normal mode vibrations. As a result, the current implementations cannot contribute to an improved prediction of relative intensity pattern from SCC-DFTB as compared to ab initio reference data.
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影响因子：
--
作者：
Hueckel, Erich
通讯作者：
Hueckel, Erich
用于计算多肽主链的红外光谱的极化力场。
DOI：
10.1021/jp8013767
发表时间：
2008
期刊：
The journal of physical chemistry. B
影响因子：
--
作者：
Verena Schultheis;Rudolf Reichold;B. Schropp;P. Tavan
通讯作者：
P. Tavan
影响因子：
--
作者：
MATSUZAWA, N;DIXON, DA
通讯作者：
DIXON, DA
DOI：
10.1007/bf01209416
发表时间：
1973-01-01
期刊：
THEORETICA CHIMICA ACTA
影响因子：
--
作者：
RINALDI, D;RIVAIL, JL
通讯作者：
RIVAIL, JL
影响因子：
4.4
作者：
Witek, HA;Morokuma, K;Stradomska, A
通讯作者：
Stradomska, A