Ab initio description of optical nonlinearities induced by impulsive broadband radiation (INPULS)

脉冲宽带辐射引起的光学非线性的从头开始描述 (INPULS)

• 批准号: 524452181
• 负责人: Professorin Dr. Caterina Cocchi
• 金额: --
• 依托单位: Institut für Physik (IFP)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/524452181?language=en
• 关键词: Ab; initio; description; optical; nonlinearities

The theoretical description of optical limiting (OL) in molecules is still in its infancy, despite the popularity gained by first-principles methods in the characterization of spectroscopic properties in these systems. Established methods based on model Hamiltonians have proven to be very effective to reproduce experimental trends. However, their dependence on empirical parameters limits dramatically their applicability to unknown compounds. The first development of an ab initio scheme for OL based on real-time time-dependent density-functional theory (RT-TDDFT), proposed by the applicant and her coworkers in 2014, has paved the way to a non-perturbative, parameter-free description of this phenomenon at affordable computational costs. However, the variety and complexity of the mechanisms contributing to OL call for dedicated analysis and further developments which are at the core of this project. Herein, we aim to develop an efficient and accurate first-principles scheme based on RT-TDDFT to predict, describe, and interpret OL and related optical nonlinearities in organic molecules. We plan to extend our seed approach to (i) identify the driving mechanisms of OL; (ii) account for the effects of electron-vibrational interactions; (iii) include in the method electrostatic coupling with the environment. Direct comparison with experiments performed by an external project partner is envisioned as a quantitative point of reference for our results. The inclusion of the developed method into an automated workflow will enable its dissemination also beyond the theorists’ community.

尽管第一性原理方法在表征分子的光谱性质方面得到了广泛的应用，但分子中光限幅的理论描述仍处于起步阶段。已建立的方法的基础上模型哈密顿已被证明是非常有效的再现实验趋势。然而，它们对经验参数的依赖极大地限制了它们对未知化合物的适用性。由申请人及其同事在2014年提出的基于实时时间依赖密度泛函理论（RT-TDDFT）的OL从头算方案的第一次开发，为以可负担的计算成本对这种现象进行非微扰、无参数描述铺平了道路。然而，导致OL的机制的多样性和复杂性要求专门的分析和进一步的发展，这是本项目的核心。在这里，我们的目标是开发一个有效的和准确的第一性原理计划的基础上RT-TDDFT预测，描述和解释OL和相关的光学非线性有机分子。我们计划将我们的种子方法扩展到（i）识别OL的驱动机制;（ii）考虑电子振动相互作用的影响;（iii）包括与环境的静电耦合。与外部项目合作伙伴进行的实验进行直接比较被设想为我们的结果的定量参考点。将所开发的方法纳入自动化工作流程将使其传播范围超出理论界。