Stress testing the ELBA water model

Abstract

The ELBA coarse-grained model describes a water molecule as a single-site Lennard-Jones particle embedded with a point dipole. ELBA was previously reported to capture several properties of real water with relatively high accuracy, while being up to two orders of magnitude more computationally efficient than atomistic models. Here, we 'stress test' the ELBA model by investigating the temperature and pressure dependences of two most important water properties, the liquid density and the self-diffusion coefficient. In particular, molecular dynamics simulations are performed spanning temperatures from 268 K up to 378 K and pressures from 1 atm up to 4000 atm. Comparisons are made with literature data from experiments and from simulations of traditional three-site atomistic models. Remarkably, the ELBA results show an overall similar (and sometimes higher) accuracy with respect to the atomistic data. We also calculate a number of additional thermodynamic properties at ambient conditions, namely isothermal compressibility, shear viscosity, isobaric heat capacity, thermal expansion coefficient and melting point. The accuracy of ELBA is relatively good compared to atomistic and other coarsegrained models.

Atomistic and Coarse-Grained Modeling of the Adsorption of Graphene Nanoflakes at the Oil–Water Interface

“…This model of water yields γ w = 60.1 ± 1.2 mJ/m 2 . At the CG level, water was simulated using the recently developed finite-sized spherical particle-dipole ELBA model, which leads to γ w = 71.2 ± 0.8 mJ/m 2 , in good agreement with the experimental value (67.9 mJ/m 2 at 323 K). The model ELBA is a single-water model, i.e., a water CG bead represents a single water molecule.…”

On the validity of the Stokes–Einstein relation for various water force fields

“…It is important to note that due to the more demanding nature of the calculation that is required for the shear viscosity of water (especially at low temperatures [38]); MD simulations are less readily available. In addition to the references that are shown in Table 1, shear viscosity studies for various water force fields have also been reported by Fuhrmans et al [43], Raabe and Sadus [44], Fuentes-Azcatl and Alejandre [45], Fuentes-Azcatl et al [46], Ding et al [47], and Köster et al [48]. The classical hydrodynamic theory of Stokes-Einstein (SE) provides a link between the intra-diffusion coefficient D (also applicable to the self-diffusion coefficient) of a particle and its radius r in a continuum with shear viscosity, η.…”

Effects of High Pressure on Phospholipid Bilayers

“…It is relevant to note that the water model employed, TIP3P, has been previously simulated under high pressures up to 4000 atm, yielding results in reasonable agreement with experiment. 57−59 In particular, referring to the density under an external pressure of 1000 atm as relevant to this work, it was calculated 59 that TIP3P only slightly overestimates the experimental value, by ∼0.01 g cm −3 . Regarding the selfdiffusion coefficient, the TIP3P value has been shown previously 58 to be consistently more than twice larger than the corresponding experimental data over a pressure range from 0 to 4000 atm.…”