Dissipative Quantum Molecular Dynamics: Density Matrix Theory and Computational Aspects

佛罗里达大学的David Micha得到了理论和计算化学计划的支持，他开发了新的理论和计算方法来描述多原子系统中局域现象的飞秒动力学，其中电子重排是由碰撞或光吸收引起的。这项研究讨论了量子自由度和类经典自由度的耦合，重点讨论了介质效应：耗散和涨落作用力以及延迟耗散对分子光谱和动力学的作用。为此，将密度算符理论和含时多电子方法结合起来，在相互作用过程中产生所需的电子势能及其耦合和电跃迁偶极子。将为这些应用开发密度矩阵传播的计算方法和相关的计算机程序。理论结果将与超快光谱的实验值进行比较，包括瞬变光谱和分子状态的光学控制。这项研究可能会对许多领域产生影响，包括开发用于光电池和光电极的新材料，这些材料在太阳能发电和燃料生产中非常重要。计算方法将适用于生物分子动力学和光生物学，如视觉、光合作用和组织的辐射损伤。将组织会议，将研究生的研究和教育结合起来，并传播跨学科成果。

David Micha of the University of Florida is supported by the Theoretical and Computational Chemistry Program to develop new theoretical and computational methods to describe the femtosecond dynamics of localized phenomena in many-atom systems where electronic rearrangement is induced by collisions or by light absorption. This research deals with the coupling of quantum and classical-like degrees of freedom with emphasis on medium effects: the role of dissipation and fluctuation forces and of delayed dissipation on molecular spectra and dynamics. For this purpose, density operator theory and time-dependent many-electron methods will be combined to generate needed electronic potential energies and their couplings, and electric transition dipoles during interactions. Computational methods for propagation of density matrices and related computer programs will be developed for the applications. Theoretical results will be compared with experimental values from ultrafast spectroscopy including transient spectra and optical control of molecular states.This research has the potential to impact a number of areas including the development of new materials for photocells and photoelectrodes, which are important in solar energy utilization for electricity and fuels production. The computational methods will be applicable to dynamics of biomolecules and photobiology, for example vision, photosynthesis, and radiation damage of tissue. Conferences will be organized to integrate research and education of graduate students, and to disseminate interdisciplinary results.