时间依赖的运动方程合集群模拟与缺陷的哈密尔顿式
Stephen H Yuwono1, Brandon C Cooper1, Tianyuan Zhang2
1Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, USA.
The Journal of chemical physics
|July 27, 2023
概括
模拟显示,切断的依赖时间的运动方程合集群方法可以产生非物理结果,如负数组,当模拟激光驱动的电子动力学附近避免过渡在分子.
科学领域:
- 量子化学 是一个量子化学.
- 理论化学 理论化学
- 计算物理 计算物理
背景情况:
- 激光诱导的电子动态对于理解分子行为至关重要.
- 截断的依赖时间的运动方程合集群 (TD-EOM-CC) 方法被广泛用于这些模拟.
- 这些方法的潜在局限性需要仔细调查.
研究的目的:
- 调查截断的TD-EOM-CC方法的准确性,特别是TD-EOM-CCSD.
- 识别和分析这些方法中出现的非物理光谱特征.
- 为了探索在化中驱动的共振电子激发的行为,在避免过路附近.
主要方法:
- 使用了时间依赖 (TD) 运动方程 (EOM) 合集群 (CC) 理论.
- 专注于TD-EOM-CC,使用单次和双次激发 (TD-EOM-CCSD).
- 在化中模拟激光驱动的电子动力学,靠近一个避免的交叉点.
主要成果:
- 识别了缺陷的相似性转换的哈密尔顿近避免交叉,导致复杂的固有值.
- 观察到非物理的负振荡器强度.
- 证明了非物理动态,包括负值或复杂值的群体,当驱动过渡到这些状态时.
结论:
- 截断的TD-EOM-CC方法可能会出现重大缺陷,特别是在避免交叉点附近.
- 不物理的光谱特征和动态可以从这些近似中产生.
- 精心验证和发展理论方法对于精确模拟激光物质相互作用至关重要.
更多相关视频
12:11Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
8.2K
10:52Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
12.8K
相关概念视频
Equilibrium Conditions for a Particle
1.2K
When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
1.2K
Euler Equations of Motion
254
Imagine a rigid body that is rotating at an angular velocity of ω within an inertial frame of reference. Along with this, picture a second rotating frame that is attached to the body itself. This frame moves along with the body and possesses an angular velocity of Ω. The total moment about the center of mass is calculated by adding the rate of change of angular momentum about the center of mass in relation to the rotating frame and the cross-product of the body's angular velocity...
254
Kinematic Equations - II
9.6K
The second kinematic equation expresses the final position of an object in terms of its initial position, the distance traveled with the initial constant velocity, and the distance traveled due to a change in velocity. Similar to the first kinematic equation, this equation is also only valid when the acceleration is constant throughout the motion of an object.
Suppose a car merges into freeway traffic on a 200 m long ramp. If its initial velocity is 10 m/s and it accelerates at 2 m/s2, then the...
Suppose a car merges into freeway traffic on a 200 m long ramp. If its initial velocity is 10 m/s and it accelerates at 2 m/s2, then the...
9.6K
Euler's Equations of Motion
498
In fluid mechanics, shear stresses arise from viscosity, which represents a fluid's internal resistance to deformation. For low-viscosity fluids, like water, these stresses are minimal, simplifying flow analysis by allowing the fluid to be treated as inviscid, or frictionless. In an inviscid fluid, shear stresses are absent, leaving only normal stresses, which act perpendicularly to fluid elements. Notably, pressure — defined as the negative of the normal stress — remains...
498
Equation of Motion for a Rigid Body
323
The movement of a rigid object can be understood through the equations that explain both translational and rotational motion about the center of mass of the object, point G. This center of mass is the point where the equation of motion for translational motion comes into play, as per Newton's Second Law.
The combined moments generated about the center of mass of the object are equal to the rate of change of the angular momentum of the body. An external force, when applied at a different...
The combined moments generated about the center of mass of the object are equal to the rate of change of the angular momentum of the body. An external force, when applied at a different...
323
Kinematic Equations - III
7.7K
The first two kinematic equations have time as a variable, but the third kinematic equation is independent of time. This equation expresses final velocity as a function of the acceleration and distance over which it acts. The fourth kinematic equation does not have an acceleration term and provides the final position of the object at time t in terms of the initial and final velocities. This equation is useful when the value of the constant acceleration is unknown.
Using the kinematic equations,...
Using the kinematic equations,...
7.7K
