Accurate Computation of the Absorption Spectrum of Chlorophyll a with Pair Natural Orbital Coupled Cluster Methods.
Accurate Computation of the Absorption Spectrum of Chlorophyll a with Pair Natural Orbital Coupled Cluster Methods.
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DOI：
10.1021/acs.jpcb.0c05761
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发表时间：
2020-10-08
期刊：
影响因子：
--
通讯作者：
Pantazis DA
中科院分区：
文献类型：
--
作者：
Sirohiwal A;Berraud-Pache R;Neese F;Izsák R;Pantazis DA
准确计算叶绿素低能激发态的能力对于理解它们在光捕获、能量转移和光合电荷分离中所起的重要作用至关重要。量子化学方法的挑战来自于电子结构问题的内在复杂性，以及在生物模型的情况下，需要考虑蛋白质-色素相互作用。在这项工作中，我们报告的电子结构计算前所未有的准确性低能量激发态的Q和B带的叶绿素a。这是通过使用新开发的域为基础的本地对自然轨道（DLPNO）的相似性变换方程的运动耦合团簇理论与单双激发（STEOM-CCSD）的实施与足够大的和灵活的基组相结合。我们的DLPNO-STEOM-CCSD计算的结果进行了比较，更近似的方法。结果表明，在与时间相关的密度泛函理论，DLPNO-STEOM-CCSD方法提供了一个平衡的性能为两个吸收带。除了垂直激发能，我们已经计算了振动光谱的Q和B带通过结合DLPNO-STEOM-CCSD和基态密度泛函理论的频率计算。这些结果作为与气相实验进行比较的基础。
The ability to accurately compute low-energy excited states of chlorophylls is critically important for understanding the vital roles they play in light harvesting, energy transfer, and photosynthetic charge separation. The challenge for quantum chemical methods arises both from the intrinsic complexity of the electronic structure problem and, in the case of biological models, from the need to account for protein–pigment interactions. In this work, we report electronic structure calculations of unprecedented accuracy for the low-energy excited states in the Q and B bands of chlorophyll a. This is achieved by using the newly developed domain-based local pair natural orbital (DLPNO) implementation of the similarity transformed equation of motion coupled cluster theory with single and double excitations (STEOM-CCSD) in combination with sufficiently large and flexible basis sets. The results of our DLPNO–STEOM-CCSD calculations are compared with more approximate approaches. The results demonstrate that, in contrast to time-dependent density functional theory, the DLPNO–STEOM-CCSD method provides a balanced performance for both absorption bands. In addition to vertical excitation energies, we have calculated the vibronic spectrum for the Q and B bands through a combination of DLPNO–STEOM-CCSD and ground-state density functional theory frequency calculations. These results serve as a basis for comparison with gas-phase experiments.
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影响因子：
5.7
作者：
Berraud-Pache, Romain;Neese, Frank;Izsak, Robert
通讯作者：
Izsak, Robert
影响因子：
4.4
作者：
de Souza, Bernardo;Farias, Giliandro;Izsak, Robert
通讯作者：
Izsak, Robert
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD
影响因子：
14.8
作者：
Croce, Roberta;van Amerongen, Herbert
通讯作者：
van Amerongen, Herbert
影响因子：
--
作者：
Condon, EU
通讯作者：
Condon, EU