This page aims to answer some common question about accessing the TDB web pages and the documents displayed there.
When you fill out the registration form, be careful to read ALL of it, all the way to the bottom. To obtain a user name and a password for the TDB database, you have to fill out the part after the headline "Additional Database Access Registration", and select the check box for "Chemical Thermodynamics". Note that you must be a citizen of an NEA member country to be granted access.
If you don't fill out this last part of the form, you will be registered as a user, but will not be sent a user name and a password.
If you think you have filled out the form and registered correctly, but still don't get a password and a user name within a week or so, please contact .
This problem can have several causes. Please verify that
Sometimes there are temporary problems with internet connections. Please wait 24 hours and try again before you decide that you cannot access the web pages. If all else fails, send mail to and ask for help. We try to answer as soon as possible, but cannot always guarantee a swift response due to the workload.
Send an e-mail to and ask for the required information. Please use the e-mail address you used when you registered to send the request.
NB: If you already have a user name and a password, and have merely forgotten what they are, do not re-register to get a new password and user name. This will only confuse our registration system, and may cause delays in making your account functional again. Please send an e-mail instead.
At the beginning of the TDB project, it was planned to scan most of the available literature for measurements, estimates and compilations of thermochemical data of relevance to the project. These "compiled" data were then inserted in the TDB database, and were previously available through the TDB online database retrieval. It should be emphasised, that these "compiled" data were entered directly from the available literature without any critical evaluation whatsoever. The idea was to facilitate the work of the different review groups within the project by providing a cover-all initial literature search. However, as NEA resources for the project were decreased over time, it became impossible to continue this work. Literature scanning is now done separately by each review team for the publications of interest to their particular review report and not by the NEA. It is now many years since this kind of general compilation was done actively by the NEA. When the online access to the TDB database was changed earlier this year, it was decided to include only the selected data, i. e. data that has been evaluated by the review teams and published in the review reports. This was done for two reasons:
Last reviewed: 23 April 2017