Time-Dependent Long-Range-Corrected Density-Functional Tight-Binding Method Combined with the Polarizable Continuum Model
Time-Dependent Long-Range-Corrected Density-Functional Tight-Binding Method Combined with the Polarizable Continuum Model
复制标题
时变长程校正密度函数紧束缚方法与极化连续体模型相结合
DOI：
10.1021/acs.jpca.9b03713
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Yoshio Nishimoto
中科院分区：
文献类型：
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作者：
永田 利明;中野 元善;美齊津 文典;Yoshio Nishimoto
在这项研究中，激发态的自由能和几何结构进行了有效的评估，使用线性响应时间依赖性的远程校正密度泛函紧束缚方法集成的极化连续模型（TD-LC-DFTB 2/PCM）。虽然LC-DFTB方法需要计算交换型项，这在计算上是相当昂贵的，但使用一个CPU核心在30分钟内完成了对真空中由1000多个原子组成的系统的激发态梯度的单次计算。对具有双发射的3-羟基黄酮进行了基准计算：TD-LC-DFTB 2/PCM计算的吸收和烯醇形式的发射波长与基于密度泛函理论使用长程校正泛函预测的波长一致;然而，预测的酮形式的发射波长存在较大误差。对20多个分子的进一步基准计算表明，与实验测量的那些相比，传统的TD-DFTB方法低估了吸收和0-0跃迁能量，而TD-LC-DFTB 2方法系统地高估了这些度量。然而，与CAM-B3 LYP方法得到的结果的协议的TD-LC-DFTB 2/PCM方法的TD-LC-DFTB 2/PCM方法的潜力。此外，将范围分离参数更改为0.15可以最大限度地减少这种偏差。
In this study, excited-state free energies and geometries were efficiently evaluated using a linear-response time-dependent long-range-corrected density-functional tight-binding method integrated with the polarizable continuum model (TD-LC-DFTB2/PCM). Although the LC-DFTB method required the evaluation of the exchange-type term, which was moderately computationally expensive, a single evaluation of the excited-state gradient for a system consisting of more than 1000 atoms in a vacuum was completed within 30 min using one CPU core. Benchmark calculations were conducted for 3-hydroxyflavone, which exhibits dual emission: the absorption and enol-form emission wavelengths calculated by TD-LC-DFTB2/PCM agreed well with those predicted based on the density functional theory using a long-range corrected functional; however, there was a large error in the predicted keto-form emission wavelength. Further benchmark calculations for more than 20 molecules indicated that the conventional TD-DFTB method underestimated the absorption and 0–0 transition energies compared with those which were measured experimentally, whereas the TD-LC-DFTB2 method systematically overestimated these metrics. Nevertheless, the agreement of the results of the TD-LC-DFTB2 method with those obtained by the CAM-B3LYP method demonstrates the potential of the TD-LC-DFTB2/PCM method. Moreover, changing the range separation parameter to 0.15 minimized this deviation.