Quality Criteria

All data included in the thermodynamic reference database are assigned identifiers for "category", "class", "source, and "quality", as is described below. This shall guide the user when applying THEREDA data to specific application cases. Namely, such information helps to compute complex systems with sparse data and disputed sets of chemical species. It also permits an estimation of consequences of uncertain system understanding or numerical data.

Data Category

F	Formation data
R	Reaction data

 

Data Classes for formation data (F)

-1	Value is internally calculated from entered category F data.
0	Per definition / convention fixed value.
1	Value is based on experimental thermochemical data.
2	Analogous value, based on experimental thermochemical data for a chemical analogue.
3	Estimated value, based on verified correlations and models for formation data.
4	Value of unknown origin (e.g. from compilations without further information).
5	Value is not consistent with other data in THEREDA.
6	Data class yet to be entered.

 

Data Classes for reaction data (R)

-1	Value is internally calculated from entered category R data.
0	Per definition / convention fixed value.
1	Value is based on experimental equilibrium data.
2	Analogous value, based on experimental equilibrium data for a chemical analogue.
3	Estimated value, based on verified correlations and models for reaction data.
4	Value of unknown origin (e. g. from compilations without further information).
5	Value is not consistent with other data in THEREDA.
6	Data class yet to be entered.

Data Classes for interaction parameters

-1	Value is internally calculated from a p, T-function.
0	Per definition / convention fixed value.
1	Parameter is derived from experimental data.
2	Analogous parameter, based on experimental data for a chemical analogue.
3	Estimated parameter, based on verified correlations and models for reaction data.
4	Tentative value for unknown interaction parameters, which cannot be estimated.
5	Parameter is not consistent with other data in THEREDA.
6	Data class yet to be entered.

 

Data Source

-1	Value is internally calculated from entered data.
0	Per definition / convention fixed value.
1	Datum adopted from an international review (e.g. CODATA, NEA-TDB) or from an internationally accepted review article (e.g. HAR/MOL1984).
2	Datum adopted from an institutional review (e.g. PSI-Nagra, FZK-INE).
3	Datum is based on several, publicely available publications (paper/report), peer-reviewed and assessed by contributors to the THEREDA project.
4	Datum is based on a single publicely available publication (paper/report), reviewed and assessed by contributors to the THEREDA project.
5	Datum is from an internal, not publicely available report, but accessible for and reviewed by contributors to the THEREDA project.
6	Data source yet to be entered

 

Quality Level

-1	Value is internally calculated from entered data.
0	Per definition / convention fixed value.
1	Reliably confirmed datum.
2	Datum is reliable within a given range of error, which is comparatively high (e.g. because of experimental problems and additional errors due to other utilized auxiliary data).
3	Questionable datum (e.g. questionable speciation model, or uncertainties with regard to with regard to the applicability of analogous data and estimation procedures), yet suitable and necessary for the description of experimental data in the system of interest.
4	Degree of reliability and applicability for model calculations not checked.
5	Checked and deemed as unsuitable for model calcualtions (e.g. because of experimental inadequacies, false assumptions during the processing of experimental data, or inadequate estimation procedure).
6	Data quality yet to be entered.

 

Addional elements for quality assurance

• All data included in THEREDA are assigned, if possible, an uncertainty.

• All data included in THEREDA must be internally consistent.

• Dependencies between data and parameter, which are crucial for internal consistency, must be annotated and visible for the user.

• As far as possible, selection of data shall be accounted for in attached documents, available for the user.

• Parameter files made available from contributors to the THEREDA-project have to undergo a series of pre-defined test calculations.