Success in Fundamental Understanding of Materials Formation from Atoms by Accurate Numerical Calculation


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.

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

Prof. Kawazoe group(Materials Design by Computer Simulation)