Assessment of Tuning Methods for Enforcing Approximate Energy Linearity in Range-Separated Hybrid Functionals.
Assessment of Tuning Methods for Enforcing Approximate Energy Linearity in Range-Separated Hybrid Functionals.
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DOI：
10.1021/ct400592a
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发表时间：
2013-09
影响因子：
5.5
通讯作者：
J. D. Gledhill;Michael J G Peach;D. Tozer
中科院分区：
文献类型：
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作者：
J. D. Gledhill;Michael J G Peach;D. Tozer
评估了一系列调谐方法，用于通过逐个系统地优化范围分离的混合泛函来强制实施近似能量线性。对一系列原子的前线轨道能量、电离势、电子亲和势和轨道能隙的精度进行了量化，并特别注意了实际实现近似能量线性的程度。与传统的泛函方法相比，这些方法可以显著改善轨道能量和轨道能隙。对于具有整数M个电子的系统，使用基于M和M+1电子系统的最高占据轨道能量的调谐范数获得最佳结果，与精确值相比，这些量的偏差仅为0.1-0.2 eV。然而，对碳原子的详细检查表明，由非线性引起的误差与在调谐中使用的计算电离势和电子亲合势的误差之间存在微妙的抵消。
A range of tuning methods, for enforcing approximate energy linearity through a system-by-system optimization of a range-separated hybrid functional, are assessed. For a series of atoms, the accuracy of the frontier orbital energies, ionization potentials, electron affinities, and orbital energy gaps is quantified, and particular attention is paid to the extent to which approximate energy linearity is actually achieved. The tuning methods can yield significantly improved orbital energies and orbital energy gaps, compared to those from conventional functionals. For systems with integer M electrons, optimal results are obtained using a tuning norm based on the highest occupied orbital energy of the M and M + 1 electron systems, with deviations of just 0.1-0.2 eV in these quantities, compared to exact values. However, detailed examination for the carbon atom illustrates a subtle cancellation between errors arising from nonlinearity and errors in the computed ionization potentials and electron affinities used in the tuning.