We introduce the basic concepts of two-dimensional electronic spectroscopy (2DES) and a general theoretical framework adopted to calculate, from first principles, the nonlinear response of multi-chromophoric systems in realistic environments. Specifically, we focus on UV-active chromophores representing the building blocks of biological systems, from proteins to nucleic acids, describing our progress in developing computational tools and protocols for accurate simulation of their 2DUV spectra. The roadmap for accurate 2DUV spectroscopy simulations is illustrated starting with benchmarking of the excited-state manifold of the chromophoric units in a vacuum, which can be used for building exciton Hamiltonians for large-scale applications or as a reference for first-principles simulations with reduced computational cost, enabling treatment of minimal (still realistic) multi-chromophoric model systems. By adopting a static approximation that neglects dynamic processes such as spectral diffusion and population transfer, we show how 2DUV is able to characterize the ground-state conformational space of dinucleosides and small peptides comprising dimeric chromophoric units (in their native environment) by tracking inter-chromophoric electronic couplings. Recovering the excited-state coherent vibrational dynamics and population transfers, we observe a remarkable agreement between the predicted 2DUV spectra of the pyrene molecule and the experimental results. These results further led to theoretical studies of the excited-state dynamics in a solvated dinucleoside system, showing that spectroscopic fingerprints of long-lived excited-state minima along the complex photoinduced decay pathways of DNA/RNA model systems can be simulated at a reasonable computational cost. Our results exemplify the impact of accurate simulation of 2DES spectra in revealing complex physicochemical properties of fundamental biological systems and should trigger further theoretical developments as well as new experiments.

我们介绍了二维电子光谱（2DES）的基本概念，以及为从第一原理中计算现实环境中多发色体系的非线性响应所采用的一般理论框架。具体来说，我们专注于代表从蛋白质到核酸的生物系统组成部分的紫外线活性发色团，描述我们在开发用于精确模拟其2DUV光谱的计算工具和协议方面的进展。从真空中发色团的激发态流形的基准测试开始，阐述了精确2DUV光谱仿真的路线图，该路线图可用于构建激子哈密顿量，以用于大规模应用，或作为简化的第一性原理仿真的参考计算成本，能够处理最少（仍然很现实）的多发色模型系统。通过采用忽略动态过程（例如光谱扩散和种群转移）的静态近似值，我们展示了2DUV如何通过跟踪双链间核素来表征二核苷和包含二聚发色单元的小肽的基态构象空间（在其天然环境中）。发色电子耦合。恢复激发态相干振动动力学和人口转移，我们观察到the分子的预测2DUV光谱与实验结果之间的显着一致性。这些结果进一步导致了对溶剂化双核苷系统中激发态动力学的理论研究，表明可以以合理的计算成本模拟沿着DNA / RNA模型系统的复杂光诱导衰变途径的长寿命激发态极小值的光谱指纹。我们的结果证明了2DES光谱精确模拟对揭示基本生物系统复杂的理化性质的影响，并应触发进一步的理论发展和新的实验。