Unveiling the Role of Termination Groups in Stabilizing MXenes in Contact with Water.

MXenes are versatile 2D materials demonstrating outstanding electrochemical and physical properties, but their practical use is limited, because of fast degradation in an aqueous environment. To prevent the degradation of MXenes, it is essential to understand the atomistic details of the reaction and to identify active sites. In this letter, we provided a computational analysis of the degradation processes at the interface between MXene basal planes and water using enhanced sampling molecular dynamics simulations and symbolic regression analysis.

Evolution of vibrational bands upon gradual protonation/deprotonation of arsinic acid HAs(O)OH in media of different polarity.

This computational work is devoted to the investigation (MP2/def2-TZVP) of the geometry and IR parameters of arsinic acid HAsOOH and its hydrogen-bonded complexes under vacuum and in media with different polarity. The medium effects were accounted for in two ways: (1) implicitly, using the IEFPCM model, varying the dielectric permittivity () and (2) explicitly, by considering hydrogen-bonded complexes of HAs(O)OH with various hydrogen bond donors (41 complexes) or acceptors (38 complexes), imitating a gradual transition to the As(OH) or AsO moiety, respectively. It was shown that the transition from vacuum to a medium with > 1 causes the As(O)OH fragment to lose its flatness.

Topologically Nontrivial Phase-Change Compound GeSbTe.

Chalcogenide phase-change materials show strikingly contrasting optical and electrical properties, which has led to their extensive implementation in various memory devices. By performing spin-, time-, and angle-resolved photoemission spectroscopy combined with the first-principles calculation, we report the experimental results that the crystalline phase of GeSbTe is topologically nontrivial in the vicinity of the Dirac semimetal phase. The resulting linearly dispersive bulk Dirac-like bands that cross the Fermi level and are thus responsible for conductivity in the stable crystalline phase of GeSbTe can be viewed as a 3D analogue of graphene.

The solution and crystal structures of a module pair from the Staphylococcus aureus-binding site of human fibronectin--a tale with a twist.

An important goal of structural studies of modular proteins is to determine the inter-module orientation, which often influences biological function. The N-terminal domain of human fibronectin (Fn) is composed of a string of five type 1 modules (F1). Despite their small size, to date F1 modules have proved intractable to X-ray structure solution, although there are several NMR structures available.