A chemical process may involve multiple adiabatic electronic states, and non-adiabatic couplings play an important role in the reaction mechanism. In this work, the effect of non-adiabatic couplings in the H+MgH;→Mg;...A chemical process may involve multiple adiabatic electronic states, and non-adiabatic couplings play an important role in the reaction mechanism. In this work, the effect of non-adiabatic couplings in the H+MgH;→Mg;+H;reaction are studied using the time-dependent wave packet method and trajectory surface hopping method. The calculated results show that the reaction follows a direct abstraction process when the non-adiabatic couplings are neglected. However, when non-adiabatic couplings are included in the calculations, a longlived excited state complex(MgH_(2)+)*can be formed during the reaction. These direct and complex-forming reaction pathways are revealed by trajectory surface hopping calculations.The non-adiabatic couplings induced complex-forming mechanism not only increases the reactivity but also has significant effect on the product vibrational state distribution.展开更多
合成氨生产如何节能降耗是业内一直在思考的问题。选用先进的合成塔内件是节能的关键。前、中置废锅组合型氨（醇）塔内件能使合成氨生产大大节省能耗。该内件由三只独立单元内件组成，一起放置于氨（醇）塔外筒中，除1单元内件中有一...合成氨生产如何节能降耗是业内一直在思考的问题。选用先进的合成塔内件是节能的关键。前、中置废锅组合型氨（醇）塔内件能使合成氨生产大大节省能耗。该内件由三只独立单元内件组成，一起放置于氨（醇）塔外筒中，除1单元内件中有一换热器外，其余2、3单元内件均为空筒；无中心管和测温套管，结构非常简单。该内件与众不同之处是，移走反应热的方法不同。不用冷管、不用冷激或层间换热，而是将每单元内件中绝热反应后高温气体从塔顶引出，依次进入前、中置废锅产4.0～7.0 M Pa过热蒸汽，降温后再进塔内另一单元内件中反应，最后出塔进热交（取消塔后废锅）。展开更多
基金supported by the National Natural Science Foundation of China(No.11774043)。
文摘A chemical process may involve multiple adiabatic electronic states, and non-adiabatic couplings play an important role in the reaction mechanism. In this work, the effect of non-adiabatic couplings in the H+MgH;→Mg;+H;reaction are studied using the time-dependent wave packet method and trajectory surface hopping method. The calculated results show that the reaction follows a direct abstraction process when the non-adiabatic couplings are neglected. However, when non-adiabatic couplings are included in the calculations, a longlived excited state complex(MgH_(2)+)*can be formed during the reaction. These direct and complex-forming reaction pathways are revealed by trajectory surface hopping calculations.The non-adiabatic couplings induced complex-forming mechanism not only increases the reactivity but also has significant effect on the product vibrational state distribution.
文摘合成氨生产如何节能降耗是业内一直在思考的问题。选用先进的合成塔内件是节能的关键。前、中置废锅组合型氨（醇）塔内件能使合成氨生产大大节省能耗。该内件由三只独立单元内件组成，一起放置于氨（醇）塔外筒中，除1单元内件中有一换热器外，其余2、3单元内件均为空筒；无中心管和测温套管，结构非常简单。该内件与众不同之处是，移走反应热的方法不同。不用冷管、不用冷激或层间换热，而是将每单元内件中绝热反应后高温气体从塔顶引出，依次进入前、中置废锅产4.0～7.0 M Pa过热蒸汽，降温后再进塔内另一单元内件中反应，最后出塔进热交（取消塔后废锅）。
