English
Related papers

Related papers: Real time quantum dynamics preaveraged over imagin…

200 papers

The exact formulation of the path integral centroid dynamics is extended to include composites of the position and momentum operators. We present the generalized centroid dynamics (GCD), which provides a basis to calculate Kubo-transformed…

Quantum Physics · Physics 2014-01-28 Atsushi Horikoshi

Path integral-based simulation methodologies play a crucial role for the investigation of nuclear quantum effects by means of computer simulations. However, these techniques are significantly more demanding than corresponding classical…

Statistical Mechanics · Physics 2018-01-17 Karsten Kreis , Kurt Kremer , Raffaello Potestio , Mark E. Tuckerman

Developing new methods for the accurate and efficient calculations of real-time quantum correlation functions is deemed one of the most challenging problems of modern condensed matter theory. Many popular methods, such as centroid molecular…

Chemical Physics · Physics 2025-10-16 Nathan London , Mohammad R. Momeni

Two of the most successful methods that are presently available for simulating the quantum dynamics of condensed phase systems are centroid molecular dynamics (CMD) and ring polymer molecular dynamics (RPMD). Despite their conceptual…

Chemical Physics · Physics 2014-07-04 Mariana Rossi , Michele Ceriotti , David E. Manolopoulos

The development and implementation of increasingly accurate methods for electronic structure calculations mean that, for many atomistic simulation problems, treating light nuclei as classical particles is now one of the most serious…

Materials Science · Physics 2016-02-12 Venkat Kapil , Joost VandeVondele , Michele Ceriotti

We propose a method to study dynamical response of a quantum system by evolving it with an imaginary-time dependent Hamiltonian. The leading non-adiabatic response of the system driven to a quantum-critical point is universal and…

Other Condensed Matter · Physics 2015-05-28 C. De Grandi , A. Polkovnikov , A. W. Sandvik

In this work, a novel ring polymer representation for multi-level quantum system is proposed for thermal average calculations. The proposed presentation keeps the discreteness of the electronic states: besides position and momentum, each…

Chemical Physics · Physics 2017-05-24 Jianfeng Lu , Zhennan Zhou

We present a simple and accurate computational method, which facilitates ab-initio path-integral molecular dynamics simulations, where the quantum mechanical nature of the nuclei is explicitly taken into account, at essentially no…

Chemical Physics · Physics 2016-04-21 Chris John , Thomas Spura , Scott Habershon , Thomas D. Kühne

Path integral molecular dynamics simulations, combined with an ab initio evaluation of interactions using electronic structure theory, incorporate the quantum mechanical nature of both the electrons and nuclei, which are essential to…

Chemical Physics · Physics 2016-02-15 Ondrej Marsalek , Thomas E. Markland

An approximate approach to quantum vibrational dynamics, "Brownian Chain Molecular Dynamics (BCMD)", is proposed to alleviate the chain resonance and curvature problems in the imaginary time-based path integral (PI) simulation. Here the…

Chemical Physics · Physics 2024-01-26 Motoyuki Shiga

We extend ring-polymer molecular dynamics (RPMD) to allow for the direct simulation of general, electronically non-adiabatic chemical processes. The kinetically constrained (KC) RPMD method uses the imaginary-time path-integral…

Statistical Mechanics · Physics 2014-03-05 Artur R. Menzeleev , Franziska Bell , Thomas F. Miller

With the path integral approach, the thermal average in a multi-electronic-state quantum systems can be approximated by the ring polymer representation on an extended configuration space, where the additional degrees of freedom are…

Numerical Analysis · Mathematics 2020-11-24 Xiaoyu Lei , Zhennan Zhou

We obtain thermostatted ring polymer molecular dynamics (TRPMD) from exact quantum dynamics via Matsubara dynamics, a recently-derived form of linearization which conserves the quantum Boltzmann distribution. Performing a contour integral…

Chemical Physics · Physics 2016-02-03 Timothy J. H. Hele

We develop a path-integral dynamics method for water that resembles centroid molecular dynamics (CMD), except that the centroids are averages of curvilinear, rather than cartesian, bead coordinates. The curvilinear coordinates are used…

Chemical Physics · Physics 2019-09-04 George Trenins , Michael J. Willatt , Stuart C. Althorpe

Including quantum mechanical effects on the dynamics of nuclei in the condensed phase is challenging, because the complexity of exact methods grows exponentially with the number of quantum degrees of freedom. Efforts to circumvent these…

Chemical Physics · Physics 2015-06-23 Mariana Rossi , Hanchao Liu , Francesco Paesani , Joel Bowman , Michele Ceriotti

We set the formalism to study the way in which the choice of canonical equilibrium initial conditions affect the real-time dynamics of quantum disordered models. We use a path integral formulation on a time contour with real and imaginary…

Disordered Systems and Neural Networks · Physics 2019-05-22 Leticia F. Cugliandolo , Gustavo S. Lozano , Nicolas Nessi

The current generation of noisy intermediate scale quantum computers introduces new opportunities to study quantum many-body systems. In this paper, we show that quantum circuits can provide a dramatically more efficient representation than…

Quantum Physics · Physics 2021-03-24 Sheng-Hsuan Lin , Rohit Dilip , Andrew G. Green , Adam Smith , Frank Pollmann

We recently obtained a quantum-Boltzmann-conserving classical dynamics by making a single change to the derivation of the `Classical Wigner' approximation. Here, we show that the further approximation of this `Matsubara dynamics' gives rise…

Chemical Physics · Physics 2015-05-20 Timothy J. H. Hele , Michael J. Willatt , Andrea Muolo , Stuart C. Althorpe

For nearly the past 30 years, Centroid Molecular Dynamics (CMD) has proven to be a viable classical-like phase space formulation for the calculation of quantum dynamical properties. However, calculation of the centroid effective force…

Chemical Physics · Physics 2022-09-15 Timothy D. Loose , Patrick G. Sahrmann , Gregory A. Voth

The use of ring polymer molecular dynamics (RPMD) for the direct simulation of electron transfer (ET) reaction dynamics is analyzed in the context of Marcus theory, semiclassical instanton theory, and exact quantum dynamics approaches. For…

Statistical Mechanics · Physics 2011-08-19 Artur R. Menzeleev , Nandini Ananth , Thomas F. Miller
‹ Prev 1 2 3 10 Next ›