The goal of this Volume "Conceptual Foundations of Materials: A standard model for ground- and excited-state properties" is to present the fundamentals of electronic structure theory that are central to the understanding and prediction of materials phenomena and properties. The emphasis is on foundations and concepts. The Sections are designed to offer a broad and comprehensive perspective of the field. They cover the basic aspects of modern electronic structure approaches and highlight their applications to the structural (ground state, vibrational, dynamic and thermodynamic, etc.) and...