Table of internationally agreed upon values coordinated by The Committee on Data for Science and Technology. Includes the standard enthalpy of formation at 298.15 K, the entropy at 298.15 K, and the quantity H°(298.15 K)-H°(0) for elements, ions, and compounds.

Thermochemical database for modelling aqueous solution chemistry, including more than 230,000 critically-assessed equilibrium constants and enthalpies for about 70,000 reactions.

Calculator for thermodynamic data in geological systems as a function of temperature, pressure, and composition. User can select a mineral solid solution and provide either mole fractions or oxide weight percentages, and specify desired temperature and pressure.

This National Institute of Standards and Technology website provides thermochemical, thermophysical, and ion energetics data. Information and data on gas-phase ion, organic, and organometallic thermochemistry, as well as thermophysical properties of selected fluid systems.

Molar heat capacity, entropy, and standard enthalpy of formation values for selected elements and compounds. Data are given at 100 degree intervals from 200 to 3000 K, and also summarized for all species at 298 K.

Summaries of experimental results for 253 mineral reactions involving 94 rock-forming minerals and the fluid components H2O, CO2, and O2. Values are given for entropy and enthalpy of formation. The dataset can also be downloaded as a complete file.

Interactive periodic table. Clicking on an element brings up a list of general properties and data, and information on its discovery, history, uses, geologic occurrence and abundance, compounds, and chemical isolation.