Half a century has passed since it became possible to understand materials at the atomic level. Experimental atomic images have been obtained, and properties have been calculated by theory and simulation. However, it is difficult to directly observe such dynamic changes experimentally because they occur in shorter time than nanoseconds. Molecular dynamics has come to be widely used as a means of visualizing these changes. Recently, with the development of supercomputers, first-principles molecular dynamics has been applied to a large number of atoms. However, the first-principles calculations used in such calculations are based on density functional theory, which is a theory that can correctly handle only the ground state, and therefore chemical reactions such as catalytic reactions involving electronic excitations cannot be handled in principle, but only collision processes between molecules can be observed.
NICHe Senior Research Fellow Yoshiyuki Kawazoe together with Research Fellow Ryoji Sahara (NIMS) and Professor Emeritus Kaoru Ohno (Yokohama National University) have developed a first-principles molecular dynamics method that correctly handles electronically excited states, which can drastically improve this serious drawback. As a first example, they succeeded in a time evolution simulation of the release of hydrogen atoms from methane molecules, which are expected to be used for the generation of large amounts of hydrogen. This method can be applied to the elucidation of phenomena involving various electronic state changes in a wide range of fields, and is currently being demonstrated by expanding the scope of investigation.
The results were published in The Journal of Chemical Physics on May 8, 2024.
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