DOE portal to access over 3 million research documents.
E-print Network: Research Communications for Scientists and Engineers - This site is a searchable gateway for preprints from sources including academic institutions, research laboratories, and individual authors. It covers such disciplines at physics, materials science, chemistry, environmental sciences, and nuclear medicine. A PrePRINT Alerts feature is available.
NIST Standard Reference Data -- Scroll to lower left to access Data Portals, such as Physical Reference Data
NTIS Condensed Matter Physics Data
National Center for Science and Engineering Statistics (NSF)
