D.A. Micha, A. Leathers, and B. Thorndyke, "Density matrix treatment of electronically excited molecular systems: Applications to gaseous and adsorbate dynamics," in Quantum Dynamics of Complex Molecular Systems, (Springer, 2006). YG くんに送ってもらったもの。ただし、これをこのままペプチドに使うのは難しそう。