Overcoming Low Orbital Overlap and Triplet Instability Problems in TDDFT
Overcoming Low Orbital Overlap and Triplet Instability Problems in TDDFT
复制标题
DOI：
10.1021/jp308662x
复制
发表时间：
2012-10-04
影响因子：
2.9
通讯作者：
Tozer, David J.
中科院分区：
文献类型：
--
作者：
Peach, Michael J. G.;Tozer, David J.
在含时密度泛函理论（TDDFT）的低轨道重叠和三重态不稳定性的问题进行了研究的一个新的基准集，包括具有挑战性的单重态和三重态激发能的本地，电荷转移，和里德伯字符。低轨道重叠的问题在很大程度上克服了单重态和三重态通过使用库仑衰减功能。对于所有类别的功能考虑，然而，与三重态不稳定性问题的错误困扰高重叠激发，并苯和聚乙炔低聚物的激发态为例。Tamm-Dancoff近似的应用减少了单重态和三重态的这些误差，同时使低重叠激发不受影响。该研究说明了重叠和稳定性之间的协同作用，并强调了一个组合，库仑衰减塔姆-丹科夫方法的成功。
Low orbital overlap and triplet instability problems in time-dependent density functional theory (TDDFT) are investigated for a new benchmark set, encompassing challenging singlet and triplet excitation energies of local, charge-transfer, and Rydberg character. The low orbital overlap problem is largely overcome for both singlet and triplet states by the use of a Coulomb-attenuated functional. For all the categories of functional considered, however, errors associated with triplet instability problems plague high overlap excitations, as exemplified by the excited states of acenes and polyacetylene oligomers. Application of the Tamm-Dancoff approximation reduces these errors for both singlet and triplet states, while leaving low-overlap excitations unaffected. The study illustrates the synergy between overlap and stability and highlights the success of a combined, Coulomb-attenuated Tamm-Dancoff approach.