A5077488472- Organic and Molecular Conductors Research
- Advanced Chemical Physics Studies
- Soil and Unsaturated Flow
- Magnetism in coordination complexes
- Physics of Superconductivity and Magnetism
- Landslides and related hazards
- Surface and Thin Film Phenomena
- Groundwater flow and contamination studies
- Quantum and electron transport phenomena
- Spectroscopy and Quantum Chemical Studies
- Molecular Junctions and Nanostructures
- Methane Hydrates and Related Phenomena
- Wave and Wind Energy Systems
- Machine Learning in Materials Science
- Graphene research and applications
- Semiconductor materials and devices
- Boron and Carbon Nanomaterials Research
- Earthquake and Tsunami Effects
- Advanced Condensed Matter Physics
- Soil Moisture and Remote Sensing
- Quantum, superfluid, helium dynamics
- Theoretical and Computational Physics
- Semiconductor materials and interfaces
- Inorganic Fluorides and Related Compounds
- Underwater Vehicles and Communication Systems
National Institute for Materials Science
2015-2024
Kanagawa Institute of Technology
2009-2024
Nagoya University
1994-2024
University of Tsukuba
2014-2024
Wakayama Department of Agriculture, Forestry and Fisheries
2023
The University of Tokyo
2009-2021
University College London
2001-2020
London Centre for Nanotechnology
2009-2020
Kumamoto University
2020
Science Council of Japan
2018
Linear-scaling methods, or have computational and memory requirements which scale linearly with the number of atoms in system, N, contrast to standard approaches cube atoms. These rely on short-ranged nature electronic structure, will allow accurate, ab initio simulations systems unprecedented size. The theory behind locality structure is described related physical properties be modelled, along a survey recent developments real-space methods are important for efficient use high-performance...
Electronic structure calculations have been instrumental in providing many important insights into a range of physical and chemical properties various molecular solid-state systems. Their importance to fields, including materials science, sciences, computational chemistry device physics, is underscored by the large fraction available public supercomputing resources devoted these calculations. As we enter exascale era, exciting new opportunities increase simulation numbers, sizes, accuracies...
Peatlands are widely regarded as a significant source of atmospheric CH 4 , potent greenhouse gas. At present, most the information on environmental emissions comes from infrequent, temporally discontinuous ground‐based flux measurements. Enormous efforts have been made to extrapolate measured emission rates establish seasonal or annual averages using relevant biogeochemical factors, such water table positions peat temperatures, by assuming that was stationary during substantial nonsampling...
An overview of the CONQUEST linear scaling density functional theory (DFT) code is given, focusing particularly on behaviour modern high-performance computing platforms. We demonstrate that essentially perfect and weak parallel (with fixed number atoms per processor core) can be achieved, DFT calculations millions are now possible.
A high performance and durable electrocatalyst for the cathodic hydrogen evolution reaction (HER) in anion exchange membrane (AEM) water electrolyzers is crucial emerging economy. Herein, we synthesized Pt–C core-shell nanoparticles (core: Pt nanoparticles, shell: N-containing carbon) were uniformly coated on hierarchical MoS2/GNF using pyrolysis of h-MoS2/GNF with a Pt-aniline complex. The core-shell@h-MoS2/GNF (with 11.3 % loading) showed HER activity lower overpotential 30 mV at 10 mA...
We describe recent progress in developing linear scaling ab initio electronic structure methods, referring particular to our highly parallel code CONQUEST. After reviewing the state of field, we present basic ideas underlying almost all and discuss specific practical details implementation. also note connection between methods embedding techniques.
Within the framework of density functional theory, we calculate electronic structure α-(BEDT-TTF) 2 I 3 at 8 K and room temperature ambient pressure with uniaxial strain along a - b -axes. We confirm existence anisotropic Dirac cone dispersion near chemical potential. also extract orthogonal tight-binding parameters to analyze physical properties. An investigation potential clarifies that effects -axis is different from -axis. The carrier densities show T dependence low temperatures, which...
While the success of density functional theory (DFT) has led to its use in a wide variety fields such as physics, chemistry, materials science and biochemistry, it long been recognised that conventional methods are very inefficient for large complex systems, because memory requirements scale $N^2$ cpu $N^3$ (where $N$ is number atoms). The principles necessary develop with linear scaling system size ($\mathcal{O}(N)$ methods) have established more than ten years, but only recently practical...
Soil water retention characteristic is an important property of soil. Indirect estimation this using easily measurable soil properties remains the research focus many scientists. In study, a general approach was proposed to derive from particle-size distribution and bulk density non-similar media concept. Effectiveness developed model tested against measured data 130 sieved soils with textures ranging sand heavy clay. The values root mean square error (RMSE) between estimated experimental...
Recent works on CH 4 emissions from peatlands have demonstrated that ebullition can be a more important emission pathway than it has been thought. However, knowledge of its features and associated environmental factors is still very limited. In this study, we investigated the quantitative relationship between amount emitted via changes in atmospheric pressure through laboratory experiment. During flux measurement period, was recorded almost exclusively air‐pressure‐declining phases. The...
Single-component molecular conductors can provide a variety of electronic states. We demonstrate here that the Dirac electron system emerges in single-component conductor under high pressure. First-principles density functional theory calculations revealed cones are formed [Pd(dddt)2] (dddt = 5,6-dihydro-1,4-dithiin-2,3-dithiolate), which shows temperature-independent resistivity (zero-gap behavior) at 12.6 GPa. The cone formation be understood by tight-binding model. points originate from...
The recent progress of linear-scaling or O(N) methods in density functional theory (DFT) is remarkable. Given this, we might expect that first-principles molecular dynamics (FPMD) simulations based on DFT could treat more realistic and complex systems using the technique. However, very few examples FPMD exist to date, information accuracy reliability limited. In this paper, show efficient robust are now possible by combination extended Lagrangian Born–Oppenheimer method, which was recently...
The gas diffusion coefficient in soil is affected by several physical parameters, including (1) air-filled porosity, (2) bulk density, (3) disturbance, (4) the kind of gases, and (5) texture. From measurement relative (D/D0) alluvial volcanic soils, effects (2), (3), on D/D0 were evaluated. Gas coefficients sieved, repacked undisturbed samples measured laboratory. increased with density at same porosity both types because proportion effective pore space for relatively during compaction...