Materials stored in CrysMAS files ( *.mat or *.crys ) are collected in a material database. The database contains user defined materials as well as materials provided by an external source (software provider, central administrator).

Materials provided by an external source are locked in the material database and can not be changed or deleted by the user. The user has total control only over locally added materials. The program keeps track of the changes in the material database. Changing the local database requires writing permission for the file material_database.mat.