Journal ArticleDOI
Proton momentum distribution in water: an open path integral molecular dynamics study.
TLDR
An extension of the staging path integral molecular dynamics method is presented, which is then employed to calculate the proton momentum distributions of water in the solid, liquid, and supercritical phases, utilizing a flexible, single point charge empirical force field to model the system's interactions.Abstract:
Recent neutron Compton scattering experiments have detected the proton momentum distribution in water. The theoretical calculation of this property can be carried out via “open” path integral expressions. In this work, present an extension of the staging path integral molecular dynamics method, which is then employed to calculate the proton momentum distributions of water in the solid, liquid, and supercritical phases. We utilize a flexible, single point charge empirical force field to model the system’s interactions. The calculated momentum distributions depict both agreement and discrepancies with experiment. The differences may be explained by the deviation of the force field from the true interactions. These distributions provide an abundance of information about the environment and interactions surrounding the proton.read more
Citations
More filters
Journal ArticleDOI
Nuclear Quantum Effects in Water and Aqueous Systems: Experiment, Theory, and Current Challenges
Michele Ceriotti,Wei Fang,Peter G. Kusalik,Ross H. McKenzie,Angelos Michaelides,Miguel A. Morales,Thomas E. Markland +6 more
TL;DR: The latest major developments in simulation algorithms and theory that have enabled the efficient inclusion of nuclear quantum effects in molecular simulations, permitting their combination with on-the-fly evaluation of the potential energy surface using electronic structure theory are reviewed.
Journal ArticleDOI
Quantum nature of the hydrogen bond
TL;DR: In this article, the authors report ab initio path integral molecular dynamics studies on the quantum nature of the hydrogen bond and show that quantum nuclear effects weaken weak hydrogen bonds but strengthen relatively strong ones.
Journal ArticleDOI
Nuclear quantum effects in solids using a colored-noise thermostat.
TL;DR: A method, based on a non-Markovian Langevin equation, to include quantum corrections to the classical dynamics of ions in a quasiharmonic system is presented, finding that results in agreement with path-integral methods can be obtained using only a fraction of the computational effort.
Journal ArticleDOI
Second generation Car–Parrinello molecular dynamics
TL;DR: In this article, the authors present a survey of the development of ab initio molecular dynamics (AIMD), where finite-temperature dynamical trajectories are generated using interatomic forces which are calculated on the fly using accurate electronic structure calculations.
Journal ArticleDOI
The vibrational proton potential in bulk liquid water and ice.
TL;DR: An empirical flexible and polarizable water model is presented which gives an improved description of the position, momentum, and dynamical (spectroscopic) distributions of H nuclei in water and a new model, TTM4-F, is parametrized against electronic structure results in order to better reproduce the polarizability surface.
References
More filters
Book
Computer Simulation of Liquids
Michael P. Allen,D. J. Tildesley +1 more
TL;DR: In this paper, the gear predictor -corrector is used to calculate forces and torques in a non-equilibrium molecular dynamics simulation using Monte Carlo methods. But it is not suitable for the gear prediction problem.
Journal ArticleDOI
Canonical dynamics: Equilibrium phase-space distributions
TL;DR: The dynamical steady-state probability density is found in an extended phase space with variables x, p/sub x/, V, epsilon-dot, and zeta, where the x are reduced distances and the two variables epsilus-dot andZeta act as thermodynamic friction coefficients.
Journal ArticleDOI
A unified formulation of the constant temperature molecular dynamics methods
TL;DR: In this article, the authors compared the canonical distribution in both momentum and coordinate space with three recently proposed constant temperature molecular dynamics methods by: (i) Nose (Mol. Phys., to be published); (ii) Hoover et al. [Phys. Rev. Lett. 77, 63 (1983); and (iii) Haile and Gupta [J. Chem. Phys. 79, 3067 (1983).
Journal ArticleDOI
Unified Approach for Molecular Dynamics and Density-Functional Theory
Roberto Car,Michele Parrinello +1 more
TL;DR: In this article, a unified scheme combining molecular dynamics and density-functional theory is presented, which makes possible the simulation of both covalently bonded and metallic systems and permits the application of density functional theory to much larger systems than previously feasible.
Book
Quantum Mechanics and Path Integrals
TL;DR: Au sommaire as discussed by the authors developed the concepts of quantum mechanics with special examples and developed the perturbation method in quantum mechanics and the variational method for probability problems in quantum physics.