About 8 years ago, I had been investigating an energy transfer process from a quantum mechanical system to another. Attached is the report. If you have interest in quantum mechanical transition and have enough time, then I recommend you to read my report, and I wish you to understand what the figure 7.1 through 7.6 mean by yourself. I am assuming that readers are acquainted with the numerical method for solving the initial value problem. I am asking you how do you view the instant of the transition from eigenstate to eigenstate.