Thermodynamics

Thermodynamical data tables

Thermodynamical databases

NIST Chemistry WebBook, provides access to data compiled and distributed by NIST under the Standard Reference Data Program. (currently free)

NIST-JANAF Thermochemical Tables (interactive, for pure substances)

NIST ThermoML Representation of Published Experimental Data (free)

IUPAC-NIST Solubility Database (not free?)
Mutual solubilities and liquid-liquid equilibria of binary, ternary and quaternary systems are presented. Typical solvents and solutes include water, sea water, heavy water, inorganic compounds, and a variety of organic compounds such as hydrocarbons, halogenated hydrocarbons, alcohols, acids, esters and nitrogen compounds. For many systems, sufficient data were available to allow critical evaluation. Data are expressed as mass and mole fractions as well as the originally reported units.
There are over 67,500 solubility measurements, compiled from 18 volumes of the IUPAC Solubility Data Series. There are about 1800 chemical substances in the database and 5200 systems, of which 473 have been critically evaluated. The database has over 1800 references.

Industrial Fluids and Chemical Engineering from NIST (partially free)

Thermophysical and Thermochemical Data from NIST (partially free)

Phase Equilibria Diagrams Database from NIST (free demo version)

REFPROP, NIST Reference Fluid Thermodynamic and Transport Properties Database ($200)
Version 9.0 includes 105 pure fluids, 5 pseudo-pure fluids (such as air) and mixtures with up to 20 components.
REFPROP is a Program, not a Database Containing Measurements. The REFPROP "database" is actually a program and does not contain any experimental information, aside from the critical and triple points of the pure fluids.
[from the FAQ:] The program uses equations for the thermodynamic and transport properties to calculate the state points of the fluid or mixture. These equations are the most accurate equations available world wide. A link to one of these equations for R-125 is given below. Their high accuracy is obtained through many coefficients in the equations, and thus the calculation speed will be slower than other equations such as the Peng-Robinson cubic equations. The equations are generally valid over the entire vapor and liquid regions of the fluid, including supercritical states; the upper temperature limit is usually near the point of decomposition of the fluid, and the upper pressure (or density) limit is defined by the melting line of the substance.

MTDATA, Phase Diagram Software from the National Physical Laboratory (public access)

Steam Tables Online, calculator based on IAPWS-IF97

NIST Thermodata public databases (mainly for alloys)

Matcalc, Materials Calculator, based on CALPHAD (public access)

PE 2000, A Powerful Tool to Correlate Phase Equilibria

CALPHAD, Computer Coupling of Phase Diagrams and Thermochemistry

NIST ThermoData Engine, based on NIST/TRC SOURCE data
User Guide
NIST TDE103a - Pure Compounds ($3790)
all major thermophysical properties (about 50 properties total) including density, vapor pressure, heat capacity, enthalpies of phase transitions, critical properties, melting and boiling points, etc.

NIST TDE 103b - Pure Compounds, Binary Mixtures, Ternary Mixtures, and Chemical Reactions ($9090)
TDE provides access to single-phase thermodynamic and transport property data, VLE, LLE, and SLE data for over 37,500 binary mixtures and 10,000 ternary mixtures, and does automated evaluation of most of those properties. Certain properties such as densities, critical, and transport properties are described by special fitting equations; phase equilibria data are described by activity coefficient models selected by the user from the set of supported models: Margules, NRTL, Redlich-Kister, UNIQUAC, van Laar, and Wilson. UNIFAC predictions are generated for mixtures covered by the various versions of the UNIFAC method, including those for which experimental data are currently not available.

DETHERM, Thermophysical Properties of Pure Substances & Mixtures (commercial)
from DECHEMA, Gesellschaft für Chemische Technik und Biotechnologie

DPP Data Preparation Package (commercial) from DECHEMA

Dortmund Data Bank (commercial), UNIFAC based

ThermoData Engine (TDE) (commercial) from NIST TRC

Pandat, integrated computational environment for phase diagram calculation and materials property simulation of multi-component systems based on CALPHAD (commercial)

FactSage, The Integrated Thermodynamic Databank System (commercial)

Thermo-Calc, software and databases for calculations involving computational thermodynamics and diffusion controlled simulations. (commercial)

DIPPR, Design Institute for Physical Properties