Title: Para-orthohydrogen conversion-solving a 90-year-old mystery

Speaker: Dr. Zhang Xia

Report time: on April 15, 2022, 9:30

Tencent meeting: 381-613-636

Introduction: 

     Dr. Zhang xia is mainly engaged in theoretical research on atom-molecular collisions. She has been to Sun Yat-sen University, Freie Universitat Amsterdam and Nijmegen University for exchange visits. She has delivered several hot topics reports at international conference, for example, Sterodynamics (2018) and International Conference on Molecular Energy Transfer in Complex Systems (2015, 2019).

Abstract: 

     Since the discovery in 1933 that paramagnetic molecules can accelerate the conversion between secondary and n-hydrogen, there has been no complete and detailed quantitative method to explain this catalytic process. Almost 90 years later, we calculate the state-state transition cross sections and rate coefficients of the collisions between paramagnetic molecules O2 and H2 for the first time by using the full quantum coupled channel scattering method, and then obtain the conversion rate of secondary hydrogen with temperature variation under the action of O2. The theoretical results are in good agreement with the recent experimental results. This part of work has important guiding significance in Nuclear magnetic resonance (NMR)and medical diagnosis.