Osamu Sugino

We present a scheme to compute the thermodynamic properties and the phase stability of materials based on parameter-free microscopic quantum theory. Taking silicon as an example we show that properties like the specific entropy, the specific volume, or the heat capacity of a solid and a liquid can be calculated accurately. In particular, we can locate the solid-liquid phase boundary and compute how thermodynamic properties change upon melting. This greatly extends the range of first-principles p

We propose efficient and stable numerical methods for simulating the electron dynamics within the time-dependent density-functional theory and the nonlocal pseudopotential. In this scheme, time evolution of the wave function is followed by self-consistently solving the time-dependent Kohn-Sham equation using the higher-order Suzuki-Trotter type split-operator method. To eliminate the numerical instability problem and increase the time step for the integration, we introduce the railway curve sche

We have performed large-scale total-energy electronic-structure calculations within the local-density approximation for the negatively charged vacancy in Si. The obtained Jahn-Teller distortion, the electronic structures, and the hyperfine coupling tensors are in good agreement with the experimental data available, indicating the validity of the one-electron theory, contrary to the prevailing picture based on model calculations.

Multi-electron, multi-proton transfer is important in a wide spectrum of processes spanning biological, chemical and physical systems. These reactions have attracted significant interest due to both fundamental curiosity and potential applications in energy technology. In this Perspective Review, we shed light on modern aspects of electrode processes in the 21st century, in particular on the recent advances and challenges in multistep electron/proton transfers at solid-liquid interfaces. Ongoing

The issue of hydrogen (H) electroadsorption on Pt(111) is revisited to settle its theoretical description within the conventional ultrahigh vacuum (UHV) surface modeling and the semilocal Kohn–Sham level of the density functional theory (DFT). By performing a converged DFT calculation, we have confirmed nearly degenerated nature of H on the fcc hollow site (Hfcc) and H on the top site (Htop) when the nuclei are treated classically, while Hfcc is significantly more stable when the zero-point ener

We have performed the first-principles total-energy calculations on the atomic diffusion of group-V impurities in Si, and have revealed the pressure effect on the activation energy of the diffusion. For the vacancy mechanism, the activation energies for P, As, and Sb decrease with pressure. For the interstitial mechanism, on the other hand, the formation energy of the interstitial impurity shows a general tendency to increase with pressure. Combining the results with the experimental data, we ha

We propose a new variational method, based on the ab initio Hartree-Fock methods, for the purpose of calculating efficiently both the equilibrium geometry and the stability of alkali-metal microclusters. Applying this method to lithium clusters, up to ${\mathrm{Li}}_{36}$, we are able to find a close correlation between the observed magic numbers and the calculated stable cluster size. Furthermore, we find that lithium clusters larger than ${\mathrm{Li}}_{26}$ have an ordered structure, while cl