; table of contents. Sec. 2. Definitions. Sec. 3. Mission. Sec. 4. Basic energy sciences. Sec. 5. Advanced scientific computing research. Sec. 6. High energy physics. Sec. 7. Biological and environmental research. Sec. 8. Fusion energy. Sec. 9. Nuclear physics. Sec. 10. Science laboratories infrastructure program. Sec. 11. Authorization of appropriations. 2. Definitions In this Act: (1) Department The term Department means the Department of Energy. (2) Director The term Director means the Director of the Office of Science of the Department. (3) National laboratory The term National Laboratory has the meaning given that term in section 2 of the Energy Policy Act of 2005 ( 42 U.S.C. 15801 ). (4) Secretary The term Secretary means the Secretary of Energy. 3. Mission Section 209 of the Department of Energy Organization Act ( 42 U.S.C. 7139 ) is amended by adding at the end the following: (c) Mission The mission of the Office of Science shall be the delivery of scientific discoveries, capabilities, and major scientific tools to transform the understanding of nature and to advance the energy, economic, and national security of the United States. . 4. Basic energy sciences (a) Program The Director shall carry out a program in basic energy sciences, including materials sciences and engineering, chemical sciences, physical biosciences, and geosciences, for the purpose of providing the scientific foundations for new energy technologies. (b) Mission The mission of the program described in subsection (a) shall be to support fundamental research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels in order to provide the foundations for new energy technologies and to support Department missions in energy, environment, and national security. (c) Basic energy sciences user facilities (1) In general The Director shall carry out a program for the development, construction, operation, and maintenance of national user facilities. (2) Requirements To the maximum extent