论文标题
使用密度基质重新归一化组技术对类胡萝卜素光激发状态的动态模拟
Dynamical simulations of carotenoid photoexcited states using density matrix renormalization group techniques
论文作者
论文摘要
我们提出了一个动力学模拟方案，以对线性多烯的高度相关激发态动力学进行建模。我们将其应用于其光激发后类胡萝卜素的内部转换过程。 We use the extended Hubbard-Peierls model, $\hat{H}_{\textrm{UVP}}$, to describe the $π$-electronic system coupled to nuclear degrees of freedom supplemented by a Hamiltonian, $\hat{H}_ε$, that explicitly breaks both the particle-hole and two-fold rotation symmetries of idealized类胡萝卜素。通过使用自适应时间依赖性DMRG（TDMRG）方法求解时间依赖性的schrödinger方程，对电子自由度进行机械处理，而核动力学则通过运动的EHRENFEST方程来处理。通过将绝热兴奋状态定义为完整哈密顿的特征状态，$ \ hat {h} = \ hat {h} _ {\ textrm {\ textrm {uvp}}+\ hat {h} {计算框架，以监视从初始光激发状态到类胡萝卜素的单线三重状态的内部转换过程。我们进一步将Lanczos-DMRG纳入TDMRG-EHRENFEST方法，以计算来自不断发展的光激发状态的瞬时吸收光谱。我们描述了DMRG的准确性和收敛标准，并表明该方法准确地描述了类胡萝卜素激发态的动力学。我们还讨论了$ \ hat {h}_ε$对内部转换过程的影响，并证明其对内部转换程度的影响可以通过Landau-Zener型过渡来描述。该方法论论文是我们对类胡萝卜素激发状态动力学的更解释性讨论的伴侣，$ \ textit {phothexcipited状态动力学和类胡萝卜素中的单线裂变} $，D。Manawadu，T。N。Georges和W. Barford，W。Barford，$ \ textit {J。物理。化学a} $（2023）。
We present a dynamical simulation scheme to model the highly correlated excited state dynamics of linear polyenes. We apply it to investigate the internal conversion processes of carotenoids following their photoexcitation. We use the extended Hubbard-Peierls model, $\hat{H}_{\textrm{UVP}}$, to describe the $π$-electronic system coupled to nuclear degrees of freedom supplemented by a Hamiltonian, $\hat{H}_ε$, that explicitly breaks both the particle-hole and two-fold rotation symmetries of idealized carotenoids. The electronic degrees of freedom are treated quantum mechanically by solving the time-dependent Schrödinger equation using the adaptive time-dependent DMRG (tDMRG) method, while nuclear dynamics are treated via the Ehrenfest equations of motion. By defining adiabatic excited states as the eigenstates of the full Hamiltonian, $\hat{H}=\hat{H}_{\textrm{UVP}}+\hat{H}_ε$, and diabatic excited states as eigenstates of $\hat{H}_{\textrm{UVP}}$, we present a computational framework to monitor the internal conversion process from the initial photoexcited state to the singlet triplet-pair states of carotenoids. We further incorporate Lanczos-DMRG to the tDMRG-Ehrenfest method to calculate transient absorption spectra from the evolving photoexcited state. We describe the accuracy and convergence criteria for DMRG, and show that this method accurately describes the dynamics of carotenoid excited states. We also discuss the effect of $\hat{H}_ε$ on the internal conversion process, and show that its effect on the extent of internal conversion can be described by a Landau-Zener-type transition. This methodological paper is a companion to our more explanatory discussion of carotenoid excited state dynamics in, $\textit{Photoexcited state dynamics and singlet fission in carotenoids}$, D. Manawadu, T. N. Georges and W. Barford, $\textit{J. Phys. Chem. A}$ (2023).
