A Review of Wave Packet Molecular Dynamics

Grabowski, Paul E.

doi:10.1007/978-3-319-04912-0_10

Cited by 6 publications

(22 citation statements)

References 84 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In WPMD, each electron is represented as a quantum wave packet, a spatially-localized complex function often implemented on a Gaussian basis [31]. A wave packet uniquely defines the state of a single electron, with the total many-body wave function being constructed from either a Hartree product or a Slater determinant [32,33], a choice that is driven by the importance of balancing exchange effects with computational cost. Equations of motion for the dynamical parameters are easily derived from variation of the time-dependent Schrodinger equation, where, for a single-Gaussian basis, they take on a simple Hamilton form [25,31].…”

Section: Introductionmentioning

confidence: 99%

“…The direct inclusion of electrons, and thus the effects of electron-ion interactions, means that WPMD intrinsically goes beyond the BO approximation. It is capable of computing electron-ion energy exchange in nonequilibrium systems, the effects of electron-ion collisions, and more generally calculating observables in quantum many-body systems [29,33].…”

Section: Introductionmentioning

confidence: 99%

“…Despite the success of eFF, exactly how the scaling parameters address these approximations is not well understood. The predictive capability is limited, and its use in new regimes should always be corroborated with other models or experimental data [33]. For example, eFF was recently shown to underestimate the ion-ion correlation in dense aluminum plasma at temperatures of a few electronvolts [5,39].…”

Section: Introductionmentioning

confidence: 99%

“…While there has been some effort made to understand the effect of a pairwise exchange in dense hydrogen [22][23][24][25]40,41], the basis set limitation has not previously been investigated. However, work involving a multiple-Gaussian basis has been used to investigate wave-packet spreading in electron-nuclear scattering [33] and ionization of a single hydrogen atom [42,43], where improvements up to a five Gaussian basis were found. Figure 1 shows improvements in the ground state energy of the hydrogen atom with an increasing number of Gaussians in the electron basis; minimal improvements are observed beyond four Gaussians.…”

Section: Introductionmentioning

confidence: 99%

“…Equations of motion for the dynamical parameters are easily derived from variation of the time-dependent Schrodinger equation [31,33,47],…”

Section: Introduction To Wave-packet Molecular Dynamicsmentioning

confidence: 99%

See 4 more Smart Citations

An Investigation into the Approximations Used in Wave Packet Molecular Dynamics for the Study of Warm Dense Matter

Angermeier

White

2021

Plasma

View full text Add to dashboard Cite

Wave packet molecular dynamics (WPMD) has recently received a lot of attention as a computationally fast tool with which to study dynamical processes in warm dense matter beyond the Born–Oppenheimer approximation. These techniques, typically, employ many approximations to achieve computational efficiency while implementing semi-empirical scaling parameters to retain accuracy. We investigated three of the main approximations ubiquitous to WPMD: a restricted basis set, approximations to exchange, and the lack of correlation. We examined each of these approximations in regard to atomic and molecular hydrogen in addition to a dense hydrogen plasma. We found that the biggest improvement to WPMD comes from combining a two-Gaussian basis with a semi-empirical correction based on the valence-bond wave function. A single parameter scales this correction to match experimental pressures of dense hydrogen. Ultimately, we found that semi-empirical scaling parameters are necessary to correct for the main approximations in WPMD. However, reducing the scaling parameters for more ab-initio terms gives more accurate results and displays the underlying physics more readily.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Equations of motion for the dynamical parameters are easily derived from variation of the time-dependent Schrodinger equation [31,33,47],…”

Section: Introduction To Wave-packet Molecular Dynamicsmentioning

confidence: 99%

See 3 more Smart Citations

An Investigation into the Approximations Used in Wave Packet Molecular Dynamics for the Study of Warm Dense Matter

Angermeier

White

2021

Plasma

View full text Add to dashboard Cite

show abstract

Ultrafast Dynamics of Electronic Resonances in Molecules Adsorbed on Metal Surfaces: A Wave Packet Propagation Approach

Aguilar-Galindo

Borisov

Díaz‐Tendero

2021

J. Chem. Theory Comput.

View full text Add to dashboard Cite

We present a wave packet propagation-based method to study the electron dynamics in molecular species in the gas phase and adsorbed on metal surfaces. It is a very general method that can be employed to any system where the electron dynamics is dominated by an active electron and the coupling between the discrete and continuum electronic states is of importance. As an example one can consider resonant moleculesurface electron transfer or molecular photoionization. Our approach is based on a 1 computational strategy allowing to incorporate ab initio inputs from Quantum Chemistry methods, such as Density Functional Theory, Hartree-Fock and Coupled Cluster.Thus, the electronic structure of the molecule is fully taken into account. The electron wave function is represented on a 3D grid in spatial coordinates, and its temporal evolution is obtained from the solution of the time dependent Schrödinger equation. We illustrate our method with an example -electron dynamics of anionic states localized on organic molecules adsorbed on metal surfaces. In particular, we study resonant charge transfer from π * orbitals of three vinyl derivatives (acrylamide, acrylonitrile, and acrolein) adsorbed on a Cu(100) surface. Electron transfer between these lowest unoccupied molecular orbitals and the metal surface is extremely fast, leading to a decay of the population of the molecular anion on the femtosecond timescale. We detail how to analyze the time-dependent electronic wave function in order to obtain the relevant information on the system: the energies and lifetimes of the molecule-localized quasi-stationary states, their associated resonant wavefunctions, and the population decay channels. In particular, we demonstrate the effect of the electronic structure of the substrate on the energy and wave vector distribution of the hot electrons injected into the metal by the decaying molecular resonance.

show abstract

Development of a new quantum trajectory molecular dynamics framework

Svensson¹,

Campbell²,

Graziani³

et al. 2023

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

An extension to the wave packet description of quantum plasmas is presented, where the wave packet can be elongated in arbitrary directions. A generalized Ewald summation is constructed for the wave packet models accounting for long-range Coulomb interactions and fermionic effects are approximated by purpose-built Pauli potentials, self-consistent with the wave packets used. We demonstrate its numerical implementation with good parallel support and close to linear scaling in particle number, used for comparisons with the more common wave packet employing isotropic states. Ground state and thermal properties are compared between the models with differences occurring primarily in the electronic subsystem. Especially, the electrical conductivity of dense hydrogen is investigated where a 15% increase in DC conductivity can be seen in our wave packet model compared with other models. This article is part of the theme issue ‘Dynamic and transient processes in warm dense matter’.

show abstract

A Review of Wave Packet Molecular Dynamics

Cited by 6 publications

References 84 publications

An Investigation into the Approximations Used in Wave Packet Molecular Dynamics for the Study of Warm Dense Matter

An Investigation into the Approximations Used in Wave Packet Molecular Dynamics for the Study of Warm Dense Matter

Ultrafast Dynamics of Electronic Resonances in Molecules Adsorbed on Metal Surfaces: A Wave Packet Propagation Approach

Development of a new quantum trajectory molecular dynamics framework

Contact Info

Product

Resources

About