Date : 2009. 10. 7, 5:00 PM Place : Mogam Hall, Bldg 500 -Abstract- Recent advances in synthetic methods and experimental techniques produced a number of interesting chemical phenomena. However, many of those phenomena are waiting for the detailed explanation for their functioning principles at the molecular level. In particular, to design a new functional material such as catalysts, the functioning mechanism should be clearly understood. To this end, both the theoreticians and experimentalists need to be cooperative. In this talk, I will introduce computational approaches in collaboration with experimental groups (though a few examples are purely theoretical) to understand molecular functions in several subjects. Depending on the time permitted, the following subjects will be included: (1) Fluorescent sensors (2) Electrogenerated or photogenerated luminescence and electrochromic behavior (3) Catalytic chemical reaction mechanism (4) Electron and proton transfer in photosystem (5) Nanoribbon: Band structure and its application (6) Others