Iterated Real-Time Path Integral Evaluation Using a Distributed Approximating Functional Propagator and Average-Case Complexity Integration

Kouri, Donald J.; Huang, Yilun; Hoffman, David K.

doi:10.1103/physrevlett.75.49

Cited by 32 publications

(51 citation statements)

References 33 publications

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“…Here, the kinetic energy operator K k=2 ͑x i , x j ͒ is represented in each dimension using distributed approximating functionals, [77][78][79][80] …”

Section: B Shared Proton Nuclear Quantum Effectsmentioning

confidence: 99%

Insights from first principles molecular dynamics studies toward infrared multiple-photon and single-photon action spectroscopy: Case study of the proton-bound dimethyl ether dimer

Moore

Iyengar

2008

The Journal of Chemical Physics

119

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We have used finite temperature ab initio molecular dynamics simulations in conjunction with computation of critical quantum nuclear effects to probe the differences between single-photon argon tagged action spectral results and infrared multiple-photon dissociation experiments for a proton bound molecular ion system. We find that the principal difference between the results in these experimental techniques is essentially that of cluster temperature. The multiple-photon dissociation experiments conducted using room temperature ions reflect a larger degree of conformational freedom compared to the colder single-photon argon tagged action spectral results. Our ab initio molecular dynamics simulation techniques accurately capture the effects of conformational sampling, adequately reproduce both spectra, and can be utilized to assign the dynamically averaged finite temperature spectra.

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“…Here, the kinetic energy operator K k=2 ͑x i , x j ͒ is represented in each dimension using distributed approximating functionals, [77][78][79][80] …”

Section: B Shared Proton Nuclear Quantum Effectsmentioning

confidence: 99%

Insights from first principles molecular dynamics studies toward infrared multiple-photon and single-photon action spectroscopy: Case study of the proton-bound dimethyl ether dimer

Moore

Iyengar

2008

The Journal of Chemical Physics

119

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“…97,98,137,138 The banded Toeplitz representation of the DAF propagator renders a great deal of efficiency to quantum propagation. 59,97,98,137 The evolution of {R C ,P C } is given by the velocity Verlet integrator, 139 which is also obtained through a third-order Trotter factorization of the classical Liouville form of the AIMD equations. 97 ıp…”

Section: Quantum Wavepacket Ab Initio Molecular Dynamics Enhancedmentioning

confidence: 99%

Quantum Wavepacket Ab Initio Molecular Dynamics: An Approach for Computing Dynamically Averaged Vibrational Spectra Including Critical Nuclear Quantum Effects

2007

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We have introduced a computational methodology to study vibrational spectroscopy in clusters inclusive of critical nuclear quantum effects. This approach is based on the recently developed quantum wavepacket ab initio molecular dynamics method that combines quantum wavepacket dynamics with ab initio molecular dynamics. The computational efficiency of the dynamical procedure is drastically improved (by several orders of magnitude) through the utilization of wavelet-based techniques combined with the previously introduced time-dependent deterministic sampling procedure measure to achieve stable, picosecond length, quantumclassical dynamics of electrons and nuclei in clusters. The dynamical information is employed to construct a novel cumulative flux/velocity correlation function, where the wavepacket flux from the quantized particle is combined with classical nuclear velocities to obtain the vibrational density of states. The approach is demonstrated by computing the vibrational density of states of [Cl-H-Cl] -, inclusive of critical quantum nuclear effects, and our results are in good agreement with experiment. A general hierarchical procedure is also provided, based on electronic structure harmonic frequencies, classical ab initio molecular dynamics, computation of nuclear quantum-mechanical eigenstates, and employing quantum wavepacket ab initio dynamics to understand vibrational spectroscopy in hydrogen-bonded clusters that display large degrees of anharmonicities.

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“…30,31,33 The wave packet dynamics is performed through an analytic, banded, Toeplitz 52 approximation to the discretized free propagator. 29,[53][54][55][56][57] Some features of this approach include: ͑a͒ accurate treatment of the electronic degrees of freedom by including hybrid density functionals ͑e.g., B3LYP͒, ͑b͒ formally exact and efficient quantum propagation where the numerical description of the wave packet adapts to the shape and position of the same to provide a flexible propagation scheme, ͑c͒ efficient treatment of large systems based on established linear scaling electronic structure techniques. [58][59][60] The current work, thus, attempts an important synergy between formally accurate approaches in quantum scattering theory 1, 5,6,9,10,12,26,[38][39][40]55,61,62 and approximate ab initio molecular dynamics methods [30][31][32][33][34]43,45,51,[63][64][65][66][67] to achieve efficient quantum dynamics of large systems.…”

Section: Introductionmentioning

confidence: 99%

Quantum wave packet ab initio molecular dynamics: An approach to study quantum dynamics in large systems

Iyengar

Jakowski

2005

The Journal of Chemical Physics

121

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A methodology to efficiently conduct simultaneous dynamics of electrons and nuclei is presented. The approach involves quantum wave packet dynamics using an accurate banded, sparse and Toeplitz representation for the discrete free propagator, in conjunction with ab initio molecular dynamics treatment of the electronic and classical nuclear degree of freedom. The latter may be achieved either by using atom-centered density-matrix propagation or by using Born-Oppenheimer dynamics. The two components of the methodology, namely, quantum dynamics and ab initio molecular dynamics, are harnessed together using a time-dependent self-consistent field-like coupling procedure. The quantum wave packet dynamics is made computationally robust by using adaptive grids to achieve optimized sampling. One notable feature of the approach is that important quantum dynamical effects including zero-point effects, tunneling, as well as over-barrier reflections are treated accurately. The electronic degrees of freedom are simultaneously handled at accurate levels of density functional theory, including hybrid or gradient corrected approximations. Benchmark calculations are provided for proton transfer systems and the dynamics results are compared with exact calculations to determine the accuracy of the approach.

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Iterated Real-Time Path Integral Evaluation Using a Distributed Approximating Functional Propagator and Average-Case Complexity Integration

Cited by 32 publications

References 33 publications

Insights from first principles molecular dynamics studies toward infrared multiple-photon and single-photon action spectroscopy: Case study of the proton-bound dimethyl ether dimer

Insights from first principles molecular dynamics studies toward infrared multiple-photon and single-photon action spectroscopy: Case study of the proton-bound dimethyl ether dimer

Quantum Wavepacket Ab Initio Molecular Dynamics: An Approach for Computing Dynamically Averaged Vibrational Spectra Including Critical Nuclear Quantum Effects

Quantum wave packet ab initio molecular dynamics: An approach to study quantum dynamics in large systems

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