Behaviors of sodium and calcium ions at the borosilicate glass-water interface: Gaining new insights through an ab initio molecular dynamics study.

We study reactivity and leaching at the calcium sodium borosilicate (CNBS)-water interface by means of a Car-Parrinello ab initio molecular dynamics simulation over a simulation time of 100 ps. With an emphasis on the comparison between the behaviors of Ca and Na cations at the CNBS glass-water interface, different mechanism events during the trajectory are revealed, discussed, and correlated with other density functional theory calculations. We show that Na ions can be released in solution, while Ca cannot leave the surface of CNBS glass.

Many-body effects at the origin of structural transitions in BO.

The structural properties of glassy diboron trioxide, g-BO, are investigated from ambient to high pressure conditions using two types of atomic force-field models that account for many-body effects. These models are parameterized by a dipole- and force-fitting procedure of reference datasets created via first-principles calculations on a series of configurations. The predictions of the models are tested against experimental data, where particular attention is paid to the structural transitions in g-BO that involve changes to both the short- and medium-range order.

NMR shifts in aluminosilicate glasses via machine learning.

Machine learning (ML) approaches are investigated for the prediction of nuclear magnetic resonance (NMR) parameters in aluminosilicate glasses, for which NMR has proven to be a cutting-edge method over the last decade. DFT computations have emerged as a new dimension for complementing these NMR methods although suffering from severe limitations in terms of size, time and computational resources consumption. While previous approaches tend to use DFT-GIPAW calculations for the prediction of NMR parameters in glassy systems, we propose to employ ML methods, characterized by a speed similar to that of classical molecular dynamics while the accuracy of ab initio methods can be reached.

Xenon solubility and formation of supercritical xenon precipitates in glasses under non-equilibrium conditions.

Estimates of noble gas solubility in glasses and minerals are important to understand the origin of these gases, particularly xenon, in the atmosphere. However, technical difficulties and ambiguities in quantifying the dissolved gases introduce large uncertainties in the solubility estimates. We present here the use of transmission electron microscopy (TEM) with in-situ noble gas ion implantation as a non-equilibrium approach for noble gas solubility estimates.

Structural study of NaO-BO-SiO glasses from molecular simulations using a polarizable force field.

Sodium borosilicate glasses NaO-BO-SiO (NBS) are complex systems from a structural point of view. Three main building units are present: tetrahedral SiO and BO (B) and triangular BO (B). One of the salient features of these compounds is the change of the B/B ratio with the alkali concentration, which is very difficult to capture in force fields-based molecular dynamics simulations.

Contribution of first-principles calculations to multinuclear NMR analysis of borosilicate glasses.

Boron-11 and silicon-29 NMR spectra of xSiO(2)-(1-x)B(2)O(3) glasses (x=0.40, 0.80 and 0.

Structural properties of a calcium aluminosilicate glass from molecular-dynamics simulations: a finite size effects study.

We study a calcium aluminosilicate glass of composition (SiO(2))(0.67)-(Al(2)O(3))(0.12)-(CaO)(0.