Research

In Kawazoe laboratory, Professor emeritus Hiroshi Yasuhara predicted that the most important contribution in the formation of materials is the electron-nucleus attractive interaction. According to this prediction, Dr. Kenta Hongo worked out a very accurate numerical calculation for hydrogen molecule by diffusion quantum Monte Carlo method, and proved it. In most of the standard textbooks, famous Heitler-London model or minimum basis molecular orbitals method are introduced, where the stability of materials is explained by a complete misunderstanding of reducing kinetic energy T and increasing potential energy V. Many similar mistakes have also been conducted by the ab initio calculations or theoretical model calculations, where only the total energy E is considered as the parameter for the stability. For isolated many-body Coulombic system, virial theorem (2T+V=0) holds and T and V are not independent. Accordingly E=T+V=-T=V/2, and when materials are formed from atoms, electrons come closer to the nucleus positions to earn potential energy, and T increases. Although this conclusion has already been stated from 60s, this is the first time to compute very accurately each part of energy with complete inclusion of electron exchange-correlations. This result was reported in Nikkei Nanobuisness journal in November and attracted a lot of interests, and will be published in International Journal of Quantum Chemistry.

HL=Heitler-London, DMC=Diffusion Quantum Monte Carlo method Charge distribution of hydrogen molecule cannot be represented by superposition of 1s orbitals.