The difference between databases from GWB and EQ3/6

[yzdm]

Hi everyone, i made a comparison between the databases from GWB and EQ3/6. There are content differences between these two databases. 

The database content of EQ3/6 is similar to that of GWB, and the titles in the same line of the table below have similar content from No. 1 to No. 8.  And No. 10&11 of EQ3/6 are break up and filled into other contents in GWB. However, the content of 'Solid solutions' in EQ3/6 and 'Oxide' in GWB seem to be the distinctive content in each database.

I want to ask whether the database of GWB contains 'solid solution', if not, what effect will have on the simulation result?

No.        EQ3/6	GWB
1         Title including Options	Header (References)
2        Miscellaneous parameters	Tables
3        Elements	Elements
4        Basis species	Basis species (B-dot parameters)
5        Auxiliary basis species	Redox couples (B-dot parameters)
6        Aqueous species	Aqueous species (B-dot parameters)
7        Solids	Minerals
8        Gases	Gases
9        Solid solutions	Oxides
10      B-dot parameters
11       References

[Brian Farrell]

Hello,

The GWB does not currently include a solid solution model. One or more minerals of a composition intermediate between two end-members can be accounted for, however, by adding minerals of discrete composition and known stability to the thermo dataset. 

Regards,

Brian Farrell
Aqueous Solutions LLC

[Brian Farrell]

With the GWB 2022 release, binary solid solutions can now be modeled. Either a Guggenheim or ideal activity model can be used, and either a continuous or discrete implementation can be chosen. Solid solutions can be defined in the thermodynamic dataset or configured by the user at run time. For more information about the model, please see section 2.5, Solid solutions, in the GWB Essentials Guide. Please see as well section 3.4.7, Solid solutions, in the Thermo datasets chapter of the GWB Reference Manual.

Regards,

Brian Farrell
Aqueous Solutions

[Brian Farrell]

For anyone who comes across this old post, in GWB 2023 the solid solution model has been extended to include some of the capabilities described for EQ3/6, such as the site-mixing model. Furthermore, the TEdit app can be used to import any EQ3/6 dataset to GWB format. And conversely, GWB datasets using the b-dot and h-m-w models can be exported to EQ3/6 format. For more information, please see 2.5 Solid solutions, 9.3.2 Importing EQ3/6 datasets, and 9.3.3 Exporting EQ3/6 datasets in the GWB Essentials Guide.

Regards,

Brian Farrell
Aqueous Solutions