Classical and path-integral molecular-dynamics study on liquid water and ice melting using non-empirical TTM2.1-F model

Abstract

The TTMF2.1-F model is a non-empirical intermolecular water potential parametrised from ab-initio calculations of the water dimer with a complete basis set limit including dispersion correction from second-order Moller-Plesset perturbation theory. In this work, using two-phase ice-water NVT molecular-dynamics (MD) simulations, we found the ice melting temperature using the TTM2.1-F potential is close to 273 K when the nuclear quantum effects (NQEs) were included using path-integral centroid MD. Detailed analysis of the radial distribution functions, angle distribution functions, and associated joint probability for both liquid water and the two-phase cases showed that the melting-point-temperature drop when using path-integral simulation is due to the weakening of hydrogen bonds vis-à-vis classically-propagated MD.

GRAPHICAL ABSTRACT

KEYWORDS:

• Quantum effect
• path integral
• molecular dynamics
• water
• melting temperature

Acknowledgements

The authors thank Peter Kusalik, Mohammad Reza Ghaani and Zdenek Futera for technical assistance and interesting discussions. NJE thanks Science Foundation Ireland for funding under grant SFI 15/ERC-I3142.

Disclosure statement

No potential conflict of interest was reported by the authors.