Path-integral dynamics of water using curvilinear centroids

Abstract

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 explicitly only when computing the potential of mean force, the components of which are re-expressed in terms of cartesian 'quasi-centroids' (so-called because they are close to the cartesian centroids). Cartesian equations of motion are obtained by making small approximations to the quantum Boltzmann distribution. Simulations of the infrared spectra of various water models over 150-600 K show these approximations to be justified: for a two-dimensional OH-bond model, the quasi-centroid molecular dynamics (QCMD) spectra lie close to the exact quantum spectra, and almost on top of the Matsubara dynamics spectra; for gas-phase water, the QCMD spectra are close to the exact quantum spectra; for liquid water and ice (using the q-TIP4P/F surface), the QCMD spectra are close to the CMD spectra at 600 K, and line up with the results of thermostatted ring-polymer molecular dynamics and approximate quantum calculations at 300 and 150 K. The QCMD spectra show no sign of the CMD 'curvature problem' (of erroneous red shifts and broadening). In the liquid and ice simulations, the potential of mean force was evaluated on the fly by generalising an adiabatic CMD algorithm to curvilinear coordinates; the full limit of adiabatic separation needed to be taken, which made the QCMD calculations 8 times more expensive than partially adiabatic CMD at 300 K, and 32 times at 150 K (and the intensities may still not be converged at this temperature). The QCMD method is probably generalisable to many other systems, provided collective bead-coordinates can be identified that yield compact mean-field ring-polymer distributions.

arXiv comment16 pages, 11 figures

References in corpus (13)

• Competing quantum effects in the dynamics of a flexible water model
• Efficient stochastic thermostatting of path integral molecular dynamics
• i-PI 2.0: A Universal Force Engine for Advanced Molecular Simulations
• How to remove the spurious resonances from ring polymer molecular dynamics
• Stochastic thermostats: comparison of local and global schemes
• Boltzmann-conserving classical dynamics in quantum time-correlation functions: Matsubara dynamics
• Derivation of a true (t->0+) quantum transition-state theory. Part I: Uniqueness and equivalence to ring-polymer molecular dynamics transition-state-theory
• Relation of centroid molecular dynamics and ring-polymer molecular dynamics to exact quantum dynamics
• Derivation of instanton rate theory from first principles
• On the Consistency of Approximate Quantum Dynamics Simulation Methods for Vibrational Spectra in the Condensed Phase
• Fine Tuning Classical and Quantum Molecular Dynamics using a Generalized Langevin Equation
• Critical role of quantum dynamical effects in the Raman spectroscopy of liquid water
• Mean-field Matsubara dynamics: Analysis of path-integral curvature effects in rovibrational spectra

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