Jump to content
Geochemist's Workbench Support Forum

How can i custom my own database?

Recommended Posts

Hi everyone,

After learning the tutorial about “Editing thermo”, i noticed that the range of temperature and pressure are limited. I do know how to modify the logK vaules using SUPCRT92, but i am not sure how to change the parameters of Deby-Huckel parameters/CO2activity coefficient terms and water activity coefficient terms, especially the CO2 1,2,3,4s and H2O 1,2,3,4s.

Where can i find those parameters or is there a software can generate them?


Share this post

Link to post
Share on other sites

Dear Yzdm,


I am not sure whether the change of activity coefficients of water and CO2 and Debye-Huckel parameters with pressure and temperature are considered in anyway in programs making GWB-formatted datasets at arbitrary temperatures and pressures. I would suggest that you check the DBCreate and K2GWB programs to see if they are considering the effect of pressure and temperature on the activity coefficients and Debye-Huckel parameters in producing GWB-formatted thermo datasets. If not, you may check these two papers and see if they have the information you are looking for:


1- Helgeson, H.C., 1969, Thermodynamics of hydrothermal systems at elevated temperatures and pressures. American Journal of Science 267, 853-877

2- Helgeson, H.C. and D.H. Kirkham, 1974, Theoretical prediction of the thermodynamic behavior of aqueous electrolytes at high pressures, and temperatures, II. Debye-Huckel parameters for activity coefficients and relative partial molal properties. American Journal of Science 274, 1199-1261


Also, I think you will find section 8.1.2 of Craig Bethke's Geochemical and Biogeochemical Reaction Modeling text on B-dot model helpful.


Hope this helps.



Melika Sharifi

Aqueous Solutions LLC

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now