Simulation of quantum zero-point effects in water using a frequency-dependent thermostat

Abstract

Molecules like water have vibrational modes with a zero-point energy well above room temperature. As a consequence, classical molecular dynamics simulations of their liquids largely underestimate the energy of modes with a higher zero-point temperature, which translates into an underestimation of covalent interatomic distances due to anharmonic effects. Zero-point effects can be recovered using path integral molecular dynamics simulations, but these are computationally expensive, making their combination with ab initio molecular dynamics simulations a challenge. As an alternative to path integral methods, from a computationally simple perspective, one would envision the design of a thermostat capable of equilibrating and maintaining the different vibrational modes at their corresponding zero-point temperatures. Recently, Ceriotti et al. (Phys. Rev. Lett. 102 020601 (2009)) introduced a framework to use a custom-tailored Langevin equation with correlated noise that can be used to include quantum fluctuations in classical molecular dynamics simulations. Here we show that it is possible to use the generalized Langevin equation with suppressed noise in combination with Nose-Hoover thermostats to efficiently impose a zero-point temperature on independent modes in liquid water. Using our simple and inexpensive method, we achieve excellent agreement for all atomic pair correlation functions compared to the path integral molecular dynamics simulation.

27 pages, 12 figs, Published version

References in corpus (13)

• Competing quantum effects in the dynamics of a flexible water model
• Nuclear quantum effects in water
• Accurate sampling using Langevin dynamics
• Efficient stochastic thermostatting of path integral molecular dynamics
• Nuclear quantum effects in solids using a colored-noise thermostat
• Colored-noise thermostats à la carte
• Anomalous Nuclear Quantum Effects in Ice
• Efficient multiple time scale molecular dynamics: using colored noise thermostats to stabilize resonances
• Quasi-harmonic approximation of thermodynamic properties of ice Ih, II, and III
• Isotope effects in ice Ih: A path-integral simulation
• Role of quantum nuclei and local fields in the x-ray absorption spectra of water and ice
• Quantum path integral simulation of isotope effects in the melting temperature of ice Ih
• Momentum distribution, vibrational dynamics and the potential of mean force in ice

Cited by in corpus (5)

• High Order Path Integrals Made Easy
• Zero-Point Energy Leakage in Quantum Thermal Bath Molecular Dynamics Simulations
• Converged Colored Noise Path Integral Molecular Dynamics Study of the Zundel Cation down to Ultra-low Temperatures at Coupled Cluster Accuracy
• Robust Binding Energy Distribution Sampling on Amorphous Solid Water Models. Method testing and validation with NH3, CO and CH4
• Using a monomer potential energy surface to perform approximate path integral molecular dynamics simulation of ab-initio water with near-zero added cost