Bulk metallic glass (BMGs) forming alloys are fascinating, which possess a wide spectrum of scientifically interesting and technologically applicable properties. Their structures remain an unsolved puzzle and the composition design criteria are desirable. They are currently among the most actively studied metallic materials. In this book, we introduce the structure models and formation criteria of metallic glasses and a structure formation theory. Phase transformations of Zr-based alloys are studied. We ask in the early stage structure formation how the valence electrons and the...