About the Database Files

Any licensed databases purchased from Thermo‑Calc Software are encrypted in files with the extension .TDC; these files cannot be edited. These are referred to as encrypted databases.

Unencrypted databases have the file extension .TDB and can be edited. For example, PURE5 or PG35 (the free databases), or a user-defined database file.

Editing the Database Initialization File or Unencrypted Database File

If you develop your own databases on a regular basis, also see About the TDB Editor.

The database initialization file is called tc_initd.tdb. Individual licenses are still required to use each database.

The file is used differently by the program depending on whether you are working with databases in Console Mode or Graphical Mode. For this reason, editing the file can be problematic if you do not understand the differences.

About Cached Database Files and Editing the Database Initialization File or Unencrypted Database File

A user-defined database is considered to be an unencrypted database because you can make changes to it.

In Graphical Mode you can add user databases via the Options window. Once you have added the user database it is available from the database list in the System Definer Configuration window.

Global Settings: System Definer to add a user database.

In Console Mode, users can decide to add their own user-defined database to the database initiation file, which then makes it available in the Console window.

Editing the Database Initialization File or Unencrypted Database File

Custom Databases: GES5 and GES6 Calculation Engine Version

As of Thermo‑Calc version 2019b, the default calculation engine is set to GES6. For custom database users, you may sometimes see messages in the log indicating that additional preparation is being done by Thermo‑Calc prior to a calculation. The preparation is carried out automatically; it is usually fast and only needed the first time a custom database is used after a modification. While databases with warnings are tolerated, databases that contain errors can only be loaded by GES6 after the errors are corrected.

The Database Checker tool uses the same parser as GES6 and can be used to verify the consistency and correctness of databases during development, before the databases are actually used.

Database Checker

To globally set the default from GES6 back to GES5, go to the Optionswindow Global General Settings tab and click Version 5 for the Preferred Gibbs Energy System setting. The SET_GES_VERSION Console Mode command is used to change GES versions for a single Thermo‑Calc session.

Contact Thermo‑Calc Software AB at info@thermocalc.com for more information about the changes or if you encounter any issues you think are related to the new version of the calculation engine.