研究了N-$_3^+$从其$^3 Σ_{\rm g}^{-}$基态激发到第一激发单重态和三重态的光解动力学。对于N $_3^+$,使用高水平电子结构计算构建了与线性几何中的$^1 Δ_{\rm g}$和$^3 Π_{\rm u}$状态相关的$^1$ A $'$、$^1$ A $''$和$^3$ A $'$电子状态的三维势能面,并表示为再现核。在MRCI+Q/aug-cc-pVTZ理论水平上计算了参考{ \it ab initio}能量。为了研究激发态的光解离动力学,由垂直激发基态分布确定了N-$_2$产物的转动和振动分布$P(v')$和$P(j')$.由于基态$^3$ A $^{''}$ PES和激发态的不同形状,在双原子碎片中产生可观的角动量$j' \sim 60$。在激发态的寿命延长到至少50 ps。值得注意的是,从采样的初始条件从热合奏和从基态波函数的维格纳分布的结果是可比的。
英文摘要:
The photodissociation dynamics of N$_3^+$ excited from its $^3 Σ_{\rm g}^{-}$ ground to the first excited singlet and triplet states is investigated. Three dimensional potential energy surfaces for the $^1$A$'$, $^1$A$''$, and $^3$A$'$ electronic states, correlating with the $^1 Δ_{\rm g}$ and $^3 Π_{\rm u}$ states in linear geometry, for N$_3^+$ are constructed using high level electronic structure calculations and represented as reproducing kernels. The reference {\it ab initio} energies are calculated at the MRCI+Q/aug-cc-pVTZ level of theory. For following the photodissociation dynamics in the excited states, rotational and vibrational distributions $P(v')$ and $P(j')$ for the N$_2$ product are determined from vertically excited ground state distributions. Due to the different shapes of the ground state $^3$A$^{''}$ PES and the excited states, appreciable angular momentum $j' \sim 60$ is generated in the diatomic fragments. The lifetimes in the excited states extend to at least 50 ps. Notably, results from sampling initial conditions from a thermal ensemble and from the Wigner distribution of the ground state wavefunction are comparable.
Ultrafast Photodissociation Dynamics and Nonadiabatic Coupling Between Excited Electronic States of Methanol Probed by Time-Resolved Photoelectron Spectroscopy
通过对时间分辨光电子能谱学实验的详细分析和电子结构计算,研究了甲醇在156 nm光激发下的电子和核动力学.光激发泵浦脉冲之后是延迟的260 nm光电离探测脉冲,以产生通过速度图成像分析的光电子。质量分辨离子的产率,测量与类似的实验条件下,被发现表现出相同的时间依赖性作为特定的光电子能谱特征。能量分辨信号的起始和衰减时间从测量的光电子谱中提取,以实现高的时间分辨率,超过20 fs的泵浦和探测脉冲持续时间。当结合{ \it ab initio}计算选定的削减通过激发态势能面,这一信息允许动态的瞬态激发分子,表现出多个核和电子的自由度,以跟踪其固有的几个飞秒的时间尺度。在15 fs的光激发范围内,我们观察到了2 $^{1}$ A $''$(S $_2$)电子态与1 $^{1}$ A $'$(S $_3$)电子态的锥形交叉,揭示了原子核在C-O伸缩和C-O-H角打开后的光解路径.
Photodissociation spectroscopy of the dysprosium monochloride molecular ion
我们对分子离子DyCl $^+$的光解离截面进行了实验和理论研究。使用集成离子阱和飞行时间质谱仪测量光子能量范围为35,500 cm $^{-1}$至47,500 cm $^{-1}$的光解离截面;我们观察到在43,000 cm $^{-1}$附近达到峰值的宽的不对称轮廓。理论截面由电子势和跃迁偶极矩确定,电子势和跃迁偶极矩采用相对论组态相互作用、价键和耦合簇方法计算。DyCl $^+$的电子结构极其复杂,因为存在多个开放电子壳层,包括4f $^{10}$构型。该分子具有9个与离子键合的电子的吸引势和99个解离成基态Dy $^+$离子和Cl原子的排斥势。我们解释了缺乏对称性的横截面,由于从一个电子占主导地位的振动基态和几个解决排斥激发态之间的过渡的多个贡献。
Photodissociation dynamics in the first absorption band of pyrrole: II. Photofragment distributions for the $^1\!A_2(πσ^*) \leftarrow \tilde{X}^1\!A_1(ππ)$ transition
Photodissociation dynamics in the first absorption band of pyrrole: I. Molecular Hamiltonian and the Herzberg-Teller absorption spectrum for the $1^1A_2(πσ^*) \leftarrow \tilde{X}^1A_1(ππ)$ transition
Quantum Mechanical Studies of Photodissociation Dynamics on Quantum Computers
Southern University of Science and Technology(南方科技大学);The University of Chicago(芝加哥大学);Dalian Institute of Chemical Physics, Chinese Academy of Sciences(中国科学院大连化学物理研究所)
Ion loss events in a cold Rb-Ca$^+$ hybrid trap: photodissociation, black-body radiation and non-radiative charge exchange
在参考文献[Phys. Rev. Lett.]的混合陷阱实验的背景下,我们从理论上研究了激光冷却的$^{87}$ Rb基态原子和$^{40}$ Ca $^+$基态离子的碰撞动力学。107,243202(2011)],导致离子损失。冷$^{87}$ Rb $^{40}$ Ca $^+$基态分子离子是通过辐射缔合产生的,我们证明了它们被黑体辐射和$^{40}$ Ca $^+$冷却激光在397~nm处保护免于光解离。这项研究产生的解释直接观察$^{87}$ Rb $^{40}$ Ca $^+$离子在实验中,在其他混合陷阱实验中使用其他物种。基于新的自旋轨道相互作用的分子数据,我们还证实了非辐射电荷交换是主要的损失过程的钙$^+$和获得的速率与实验观察和以前的计算。
Precision measurements and test of molecular theory in highly-excited vibrational states of H$_2$ $(v=11)$
精确的$EF{}^1Σ^+_g-X{}^1Σ^+_g$跃迁能量在分子氢中被确定为跃迁起源于具有高激发振动量子数$v=11$的水平,在基态电子状态。无多普勒双光子光谱应用于振动激发H $_2^*$,产生通过光解H $_2$ S,产生的过渡频率与$45$ MHz或$0.0015$ cm $^{-1}$的精度。一个重要的改进是通过自电离$7pπ$电子里德堡态的共振激发来增强检测效率,从而由于降低的ac-斯塔克效应而导致窄跃迁。使用已知的$EF$能级能量,以通常为0.002 cm $^{-1}$的精度导出$X(v=11, J=1,3-5)$态的能级能量。这些实验值是在极好的协议,并比从最先进的从头计算分子理论计算,包括相对论和QED的贡献得到的结果更准确。
Constrained Nuclear-Electronic Orbital Time-Dependent Density Functional Theory for Excited-State Dynamics with Nuclear Quantum Effects
Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison(威斯康星大学麦迪逊分校理论化学研究所和化学系);Center for Advanced Materials Research, Beijing Normal University(北京师范大学先进材料研究中心)
Time-Resolved Ultrafast Transient Polarization Spectroscopy to Investigate Nonlinear Processes and Dynamics in Electronically Excited Molecules on the Femtosecond Time Scale
Transferable excited-state dynamics enable screening of fluorescent protein chromophores
Leipzig University(莱比锡大学);Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI), Dresden/Leipzig(德累斯顿/莱比锡可扩展数据分析与人工智能中心 (ScaDS.AI))
The rust challenge -- On the correlations between electronic structure, excited state dynamics and photoelectrochemical performance of hematite photoanodes for solar water splitting