Real-space solution to the electronic structure problem for nearly a million electrons.

We report a Kohn-Sham density functional theory calculation of a system with more than 200 000 atoms and 800 000 electrons using a real-space high-order finite-difference method to investigate the electronic structure of large spherical silicon nanoclusters. Our system of choice was a 20 nm large spherical nanocluster with 202 617 silicon atoms and 13 836 hydrogen atoms used to passivate the dangling surface bonds. To speed up the convergence of the eigenspace, we utilized Chebyshev-filtered subspace iteration, and for sparse matrix-vector multiplications, we used blockwise Hilbert space-filling curves, implemented in the PARSEC code.

Space-Filling Curves for Real-Space Electronic Structure Calculations.

Hamiltonian matrices for Kohn-Sham calculations implemented in real space are often large (millions by millions) but very sparse. This poses challenges and opportunities for iterative eigensolvers, which often require a large number of matrix-vector multiplications. As a consequence, an efficient parallel sparse matrix-vector multiplication algorithm is desired.

Investigation of the Water Adsorption Properties and Structural Stability of MIL-100(Fe) with Different Anions.

Investigating metal-organic frameworks (MOFs) as water adsorbents has drawn increasing attention for their potential in energy-related applications such as water production and heat transformation. A specific MOF, MIL-100(Fe), is of particular interest for its large adsorption capacity with the occurrence of water condensation at a relatively low partial pressure. In the synthesis of MIL-100(Fe), depending on the reactants, structures with varying anion terminals (e.

Investigating the Potential of Single-Walled Aluminosilicate Nanotubes in Water Desalination.

Water shortage has become a critical issue. To facilitate the large-scale deployment of reverse-osmosis water desalination to produce fresh water, discovering novel membranes is essential. Here, we computationally demonstrate the great potential of single-walled aluminosilicate nanotubes (AlSiNTs), materials that can be synthesized through scalable methods, in desalination.

Relationships among the structural topology, bond strength, and mechanical properties of single-walled aluminosilicate nanotubes.

Carbon nanotubes (CNTs) are regarded as small but strong due to their nanoscale microstructure and high mechanical strength (Young's modulus exceeds 1000 GPa). A longstanding question has been whether there exist other nanotube materials with mechanical properties as good as those of CNTs. In this study, we investigated the mechanical properties of single-walled aluminosilicate nanotubes (AlSiNTs) using a multiscale computational method and then conducted a comparison with single-walled carbon nanotubes (SWCNTs).