Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie der Universität Bonn, Beringstr. 4, D-53115Bonn, Germany.
Laboratory of Theoretical Chemistry, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles 61, B-5000Namur, Belgium.
J Phys Chem A. 2022 Oct 20;126(41):7534-7547. doi: 10.1021/acs.jpca.2c02395. Epub 2022 Oct 6.
This work presents the theoretical background to evaluate two-photon absorption (2PA) cross-sections in the framework of simplified time-dependent density functional theory (sTD-DFT). Our new implementation allows the ultrafast evaluation of 2PA cross-sections for large molecules based on a regular DFT ground-state determinant as well as a variant employing our tight-binding sTD-DFT-xTX flavor for very large systems. The method is benchmarked against higher-level calculations for -stilbene and typical fluorescent protein chromophores. For eGFP, a quadrupolar chromophore and its branched version, the flavine mono-nucleotide, and the iLOV protein, we compare sTD-DFT 2PA spectra to experimental ones. This includes extension and testing of our all-atom quantum chemistry methodology for the evaluation of 2PA for a system of ∼2000 atoms, providing striking agreement with the experimental spectrum.
本文提出了在简化含时密度泛函理论（sTD-DFT）框架下评估双光子吸收（2PA）截面的理论背景。我们的新实现允许基于正则 DFT 基态行列式以及我们的紧束缚 sTD-DFT-xTX 变体对大型分子进行超快 2PA 截面评估，非常适用于非常大的系统。该方法通过与更高水平的计算（例如 - 二苯乙烯和典型的荧光蛋白发色团）进行基准测试。对于 eGFP（四极发色团及其分支版本）、黄素单核苷酸和 iLOV 蛋白，我们将 sTD-DFT 2PA 光谱与实验光谱进行比较。这包括扩展和测试我们用于评估约 2000 个原子系统 2PA 的全原子量子化学方法，与实验光谱惊人地吻合。
