Ernest Bauer 
Quantum Theory of Chemical Reaction Rates [PDF ebook] 

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. We say that this state must be formed if there is to be a reaction Once the state has been formed it will have some definite (statistical) life.time, after which it can presumably break up into AB C or into A bc, both of which will in general be energetically accessible from (abc).