ChemSpider is a free chemical structure database providing fast text and structure search access to over 32 million structures from hundreds of data sources.

GeoReM is a Max Planck Institute database for reference materials of geological and environmental interest, such as rock powders, synthetic and natural glasses as well as mineral, isotopic, biological, river water and seawater reference materials. It contains published analytical data and compilation values (major and trace element concentrations and mass fractions, radiogenic and stable isotope ratios). GeoReM covers all important metadata about the analytical values such as uncertainty, analytical method and laboratory. Sample information and references are also included. GeoReM contains almost 3,400 reference materials, about 46,200 analyses from almost 10,000 papers, and preferred analytical values (State: November 2017).

ICSD is the world’s largest database for fully identified inorganic crystal structures. It currently contains about 193,000 peer-reviewed data entries including their atomic coordinates. Updates are made twice a year (in spring and in fall) with data taken from scientific journals and other sources. Thanks to these many heterogeneous data sources the database has a wide coverage. ICSD is also updated retroactively. The oldest records date back to the year 1913 and contain information from publications by William Henry Bragg and his son.