Beyond-dipole van der Waals contributions within the Many-Body Dispersion framework

By introducing a suitable range-separation of the Coulomb coupling in analogy to [A. Ambrosetti et al. JCP 140, 18A508 (2014)], here we extend the Many-Body Dispersion (MBD) approach to include beyond-dipole van der Waals interactions at a full many-body level, in combination with semi-local density functional theory. A reciprocal-space implementation is further introduced in order to efficiently treat periodic systems. Consistent reliability is found frommolecular dimers to large supramolecular complexes and two-dimensional systems. The large weight of both many-body effects and multipolar terms illustrates how a correct description of vdW forces in large-scale systems requires full account of both contributions, beyond standard pairwise dipolar approaches.

Direct correlation of oxygen adsorption on platinum-electrolyte interfaces with the activity in the oxygen reduction reaction

The oxygen reduction reaction (ORR) on platinum catalysts is essential in fuel cells. Quantitative predictions of the relative ORR activity in experiments, in the range of 1 to 50 times, have remained challenging because of incomplete mechanistic understanding and lack of computational tools to account for the associated small differences in activation energies (<2.3 kilocalories per mole). Using highly accurate molecular dynamics (MD) simulation with the Interface force field (0.1 kilocalories per mole), we elucidated the mechanism of adsorption of molecular oxygen on regular and irregular platinum surfaces and nanostructures, followed by local density functional theory (DFT) calculations. The relative ORR activity is determined by oxygen access to platinum surfaces, which greatly depends on specific water adlayers, while electron transfer occurs at a similar slow rate. The MD methods facilitate quantitative predictions of relative ORR activities of any platinum nanostructures, are applicable to other catalysts, and enable effective MD/DFT approaches.

Laplacian free and asymptotic corrected semilocal exchange potential applied to the band gap of solids

Improved band gap of n-type semiconductor ZrS2 within semi-local density functional theory is shown. The band gap of mBR-TBMBJ agrees well with the hybrid HSE06 functional.

Effect of Hartree–Fock pseudopotentials on local density functional theory calculations

Optimal choice of the element-specific pseudopotential improves the band gap.

Theoretical Study of Atoms Filled in Carbon Nanotubes

The nano-sized quasi-one dimensional hollow cores of carbon nanotubes make it possible for them to be filled with and wetted by foreign materials. With C, S and Se atoms as example, we have studied the filling and wetting of these atoms into carbon nanotubes from local density functional theory in first principles calculations. The results suggest that the effect of nanotube length is negligible when it exceeds 3.6 Å, there is a relation between nanotube diameter and filling and wetting. Our studies would be important implications for the further use of carbon nanotubes.