Ji Chen

Dr. Ji Chen focuses on developing cutting-edge full quantum computational simulation methods to provide theoretical perspectives to fundamental and interdisciplinary problems in physics, chemistry, biology, energy, and environmental sciences, providing an approach for the development of key industrial technologies. 

Full quantum simulation achieves an intelligent sampling of the full quantum space of electrons and nuclei, and is the most accurate approach to simulate molecules and materials without any empirical parameters and requirement of human intuitions.

Ammonium ion sieving is the most challenging problem in the water purification industry. A comprehensive understanding of possible structures of ammonium ions in water and their interaction mechanism is very important. With collaborators, Dr. Chen has revealed the hydrated structures and dynamics of ammonium ions in water from quantum principles. Specifically, their study finds that ammonium ion is hydrated with six water molecules, which is a magic number that allows its fast rotation in liquid water. Their research provides important theoretical guidelines for designing ammonium sieving nano-membranes, paving the way for efficient water purification and an economical global water supply.

Titanium dioxide is considered one of the most important catalysts in water solar splitting. The understanding of its structure holds great significance. However, in previous studies, the electronic structure of titanium dioxide is a matter of debate due to the limitations of experimental characterizations and theoretical accuracy. Dr. Chen with his colleagues have accurately calculated the electronic structure of titanium dioxide and revealed for the first time that the true ground state of oxygen vacancy is a singlet spin state. In addition, they have found theoretical relations between the water splitting efficiency and the substrate electronic state. Based on these findings, they have proposed design principles for efficient water-splitting solar cells, providing clean energy solutions.

In addition, Dr. Chen has made important contributions to the field of full quantum physics in condensed matter and materials, including the study of nuclear quantum effects in liquid hydrogen and the prediction of two-dimensional ice were all pioneering works of the field.