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NIST Standard Reference Database 202 Web Thermo Tables (WTT) - Lite Edition

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This web application provides access to a collection of critically evaluated thermodynamic property data for pure compounds with a primary focus on organics. These data were generated through dynamic data analysis, as implemented in the NIST ThermoData Engine software package. As of November, 2010, WTT - Lite Edition contains information on 150 commonly-used compounds and access to a total of 86407 evaluated experimental data points.

Various search options based on compound information (empirical formula, partial name, molecular weight) are provided. Data presentation features an interactive JavaScript-based Web interface with dynamic window-in-window navigation. Dynamic table generation based upon user input and interactive data plotting capabilities are also provided. Unlimited data retrieval and their local storage and use are permitted. For details regarding analytical methods and interacting with the interface, see the site user's guide.

Evaluated properties that appear in the WTT are (note that all listed properties are not necessarily available for all included compounds):

Critical Properties

Critical temperature
Critical pressure
Critical density

Phase Transition Properties

Triple point temperature
Boiling point
Vapor pressure
Sublimation pressure
Condensed-phase boundary pressure
Enthalpy of vaporization
Enthalpy of fusion
Enthalpy of crystalline phase transition
Volumetric Properties
Mass density
Isobaric coefficient of expansion
Isothermal compressibility
Thermal pressure coefficient
2nd virial coefficient
3nd virial coefficient
Adiabatic compressibility
Energetic Properties
Enthalpy of formation
Heat capacity at constant pressure
Heat capacity at constant volume
Heat capacity at saturation
Pressure coefficient of enthalpy
Joule-Thomson coefficient
Transport Properties

Thermal conductivity

Additional Properties

Speed of sound
Index of refraction
Surface tension

Complimentary WTT-Lite data availability information (properties provided for a given compound, ranges of validity, number of experimental data points points) can be accessed by those without a subscription at A complete list of compounds present in the Lite version of the database is provided here.

Click to view the subscription License Agreement before ordering.

Pricing Information:

Access to WTT - Lite Edition is subscription-based; the annual license fees are listed below:

onlineIndividual License - Individual License $200.00

onlineSmall Institution - Small Institution (2 to 500 users) $500.00

onlineMedium Institution - Medium Institution (501 to 2000 users) $1000.00

onlineLarge Institution - Large Institution (2001+ users) $1500.00

 For more information please contact:

Standard Reference Data Program
National Institute of Standards and Technology
100 Bureau Dr., Stop 8500
Gaithersburg, MD 20899-8500
(301) 975-2200(VOICE) / (301) 975-4553 (FAX) / Contact Us


The scientific contact for this database is:
Kenneth Kroenlein, Ph.D
Thermodynamics Research Center (TRC)
NIST Applied Chemicals and Materials Division
325 Broadway MS 647.01Boulder, CO 80305-3337
303 497-3952 Phone 
TRC Home Page:

Keywords: thermodynamics, thermophysics, recommended data, critically evaluated data, thermophysical properties, TRC, Thermodynamics Research Center