Pulay forces from localized orbitals optimized in situ using a psinc basis set.
Pulay forces from localized orbitals optimized in situ using a psinc basis set.
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DOI：
10.1063/1.4728026
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发表时间：
2012-06
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影响因子：
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通讯作者：
Ãlvaro Ruiz-Serrano;N. Hine;Chris-Kriton Skylaris
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文献类型：
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作者：
Ãlvaro Ruiz-Serrano;N. Hine;Chris-Kriton Skylaris
在原位优化一组本地化轨道相对于一个系统的可改进的基础设置独立的原子的位置，如psinc函数，将理论上消除的总离子力的修正，由于普拉力。我们证明，严格的本地化约束，特别是与小的本地化区域，可以有不可忽略的Pulay力，必须计算作为一个校正的赫尔曼-费曼部队在基态。几何优化计算，这在很大程度上依赖于准确评估的总离子力，显示出更好的收敛时，Pulay力。更常规的情况下，其中局部轨道保持固定到伪原子轨道多个基组，也受益于这种实现。我们已经在几个测试案例中验证了该方法，包括具有1045个原子的DNA片段。
In situ optimization of a set of localized orbitals with respect to a systematically improvable basis set independent of the position of the atoms, such as psinc functions, would theoretically eliminate the correction due to Pulay forces from the total ionic forces. We demonstrate that for strict localization constraints, especially with small localization regions, there can be non-negligible Pulay forces that must be calculated as a correction to the Hellmann-Feynman forces in the ground state. Geometry optimization calculations, which rely heavily upon accurate evaluation of the total ionic forces, show much better convergence when Pulay forces are included. The more conventional case, where the local orbitals remain fixed to pseudo-atomic orbital multiple-ζ basis sets, also benefits from this implementation. We have validated the method on several test cases, including a DNA fragment with 1045 atoms.