This book collects recent topics of theoretical chemistry for advanced nanomaterials from the points of view of both computational and experimental chemistry. It is written for computational and experimental chemists, including undergraduate students, who are working with advanced nanomaterials, where collaboration and interplay between computation and experiment are essential. After the general introduction of nanomaterials, several computational approaches are explained in Part II. Each chapter presents not only calculation methods but also concrete calculation results for advanced nanomaterials. Hydride ion conducting nanomaterials, high-k dielectric nanomaterials, and organic electronics are focused on. In Part III, the interplay between computational and experimental approaches is explained. The chapters show