English
Related papers

Related papers: Nuclear quantum effects in molecular dynamics simu…

200 papers

The quantum thermal average plays a central role in describing the thermodynamic properties of a quantum system. Path integral molecular dynamics (PIMD) is a prevailing approach for computing quantum thermal averages by approximating the…

Numerical Analysis · Mathematics 2024-06-25 Xuda Ye , Zhennan Zhou

We investigate whether making the friction spatially dependent on the reaction coordinate introduces quantum effects into the thermal reaction rates for dissipative reactions. Quantum rates are calculated using the numerically exact…

The accurate incorporation of nuclear quantum effects in large-scale molecular dynamics (MD) simulations remains a significant challenge. Recently, we combined constrained nuclear-electronic orbital (CNEO) theory with classical MD and…

Chemical Physics · Physics 2023-01-11 Zehua Chen , Yang Yang

The precise description of quantum nuclear fluctuations in atomistic modelling is possible by employing path integral techniques, which involve a considerable computational overhead due to the need of simulating multiple replicas of the…

Chemical Physics · Physics 2017-03-23 Venkat Kapil , Jörg Behler , Michele Ceriotti

We study the role of quantum fluctuations of atomic nuclei in the real-time dynamics of non-equilibrium macro-molecular transitions. To this goal we introduce an extension of the Dominant Reaction Pathways (DRP) formalism, in which the…

Biological Physics · Physics 2015-05-20 S. a Beccara , G. Garberoglio , P. Faccioli

We describe a path-integral approach for including nuclear quantum effects in non-adiabatic chemical dynamics simulations. For a general physical system with multiple electronic energy levels, a corresponding isomorphic Hamiltonian is…

Statistical Mechanics · Physics 2018-06-05 Xuecheng Tao , Philip Shushkov , Thomas Miller

The properties of molecules and materials containing light nuclei are affected by their quantum mechanical nature. Modelling these quantum nuclear effects accurately requires computationally demanding path integral techniques. Considerable…

Chemical Physics · Physics 2020-04-22 Venkat Kapil , David M. Wilkins , Jinggang Lan , Michele Ceriotti

A general and rigorous methodology to compute the quantum equilibrium isotope effect is described. Unlike standard approaches, ours does not assume separability of rotational and vibrational motions and does not make the harmonic…

Chemical Physics · Physics 2015-05-13 Tomas Zimmermann , Jiri Vanicek

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

Ab initio molecular dynamics (AIMD) is a powerful tool to predict properties of molecular and condensed matter systems. The quality of this procedure is based on accurate electronic structure calculations. The development of quantum…

We have applied path integral simulations, in combination with new ab initio based water potentials, to investigate nuclear quantum effects in liquid water. Because direct ab initio path integral simulations are computationally expensive, a…

Chemical Physics · Physics 2015-04-21 Thomas Spura , Christopher John , Scott Habershon , Thomas D. Kühne

An exact approach to compute physical properties for general multi-electronic-state (MES) systems in thermal equilibrium is presented. The approach is extended from our recent progress on path integral molecular dynamics (PIMD) [J. Chem.…

Chemical Physics · Physics 2017-11-22 Xinzijian Liu , Jian Liu

Modeling nuclear quantum effects is required for accurate molecular dynamics (MD) simulations of molecules. The community has paid special attention to water and other biomolecules that show hydrogen bonding. Standard methods of modeling…

Chemical Physics · Physics 2020-07-06 Vikram Sundar , David Gelbwaser-Klimovsky , Alan Aspuru-Guzik

A generalized Langevin equation with quantum baths (QMD) for thermal transport is derived with the help of nonequilibrium Green's function (NEGF) formulation. The exact relationship of the quasi-classical approximation to NEGF is…

Mesoscale and Nanoscale Physics · Physics 2009-12-23 Jian-Sheng Wang , Xiaoxi Ni , Jin-Wu Jiang

Nuclear quantum effects and non-Born--Oppenheimer effects play a vital role in many chemical and biological processes, motivating the incorporation of such effects into dynamical simulations. In real-time nuclear--electronic orbital…

Chemical Physics · Physics 2026-05-27 Nicholas J. Boyer , Sharon Hammes-Schiffer

We devise an efficient scheme to determine vibrational properties from Path Integral Molecular Dynamics (PIMD) simulations. The method is based on zero-time Kubo-transformed correlation functions and captures the anharmonicity of the…

Materials Science · Physics 2021-06-30 Tommaso Morresi , Lorenzo Paulatto , Rodolphe Vuilleumier , Michele Casula

The nonequilibrium dynamics of quantum fields is studied in inflationary cosmology, with particular emphasis on applications to the problem of post-inflation reheating. The Schwinger-Keldysh closed-time-path (CTP) formalism is utilized…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stephen A. Ramsey

Quasicentroid molecular dynamics (QCMD) is a path-integral method for approximating nuclear quantum effects in dynamics simulations, which has given promising results for gas- and condensed-phase water. Here, by simulating the infrared…

Chemical Physics · Physics 2021-11-29 Christopher Haggard , Vijay Ganesh Sadhasivam , George Trenins , Stuart C. Althorpe

In this study we investigate the nuclear quantum effects (NQEs) on the acidity constant (pKA) of liquid water isotopologues at the ambient condition by path integral molecular dynamics (PIMD) simulations. We compared simulations using a…

Chemical Physics · Physics 2021-03-17 Bo Thomsen , Motoyuki Shiga

The Lindblad equation determines the time evolution of the density operator of open quantum systems. While valid for any system size, its use is, in practice, restricted to prototype/surrogate models with the aim of tackling specific…

Quantum Physics · Physics 2026-04-07 Benedikt M. Reible , Somayeh Ahmadkhani , Luigi Delle Site