Structure and energetics of molecular point defects in ice Ih.

Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo.

High quality reference data from diffusion Monte Carlo calculations are presented for bulk sI methane hydrate, a complex crystal exhibiting both hydrogen-bond and dispersion dominated interactions. The performance of some commonly used exchange-correlation functionals and all-atom point charge force fields is evaluated. Our results show that none of the exchange-correlation functionals tested a...

Computational Study of Proton Ordering in Ice and Icelike Systems

Recently, there has been a lot of interest to computationally study ice and icelike systems. Simulating such structures, using ab initio methods require atomic level models. However, creating adequate models for ice is challenging, as there are a huge number of isomers for any ice formation. Two factors contribute to the number of isomers: (i) the positions of oxygens that give rise to various ...

Configurational energetics in ice ih probed by compton scattering.

Temperature-induced changes in the ground-state electron momentum density of polycrystalline ice Ih are studied with high accuracy by Compton scattering utilizing synchrotron radiation. A unique feasibility of the technique to provide direct experimental information on configurational enthalpies and heat capacities is demonstrated. The configurational enthalpy, obtained with an accuracy of 1.5 ...

Dielectric constant of ice Ih and ice V: a computer simulation study.

In this work, we exploit an efficient algorithm for the sampling of hydrogen-bond networks in order to study the order/disorder transition and the dielectric properties of ice Ih. Our results show that all of the rigid point charge models studied, TIP4P/Ice, TIP4P/2005, TIP4P, and SPC/E, yield a very low dielectric constant as compared with experiment. The analysis of the polarization factor, G...

QUANTUM MECHANICAL EXAMINATION OF ORIENTATIONAL DEFECTS IN ICE Ih