Jump to content
Geochemist's Workbench Support Forum

N-R didn't converge after 999 its.


Frank Bok
 Share

Recommended Posts

Hello,

 

I've created a minimal database with data for Na+, Cl- and some Europium(III) hydrolysis species. GWB (9.0.3) gives no errors when loading this database (Europium_test.dat).

With this database I want to do a Eu speciation calculation as a function of pH (Eu-Hydrolysis.rea). But GWB allways stops with the message:

 

Solving for initial system.

 

Loaded: 9 aqueous species,

1 minerals,

0 gases,

0 surface species,

5 elements,

0 oxides.

 

Reading conductivity data from: C:\Users\fb5950\GWB\Gtdata\conductivity.dat

N-R didn't converge after 999 its., maximum residual = 1, Xi = 0.0000

Largest residual(s):

Resid Resid/Totmol Cbasis

---------------------------------------------------------

Cl- 1.007e+200 1 3.406e-109

Eu+++ 5.109e+200 1 1.467e-108

Na+ 1.007e+200 1 3.405e-109

---------------------------------------------------------

 

Could you help me with this, please!

 

Thanks and best regards,

Frank

Link to comment
Share on other sites

Hi Frank,

 

After messing around with your dataset, I found I could get your React script to run once I set a value for the c H2O-1 coefficient at 25 C. This is the first term used in the water activity calculation (see the Geochemical and Biogeochemical Reaction Modeling text, equation 8.8). I just took the value of 1.45397 from thermo.dat.

 

Regards,

 

Brian Farrell

Aqueous Solutions LLC

Link to comment
Share on other sites

Hi Brian,

 

thank you for your quick response and help. It seems our parameter file generator for the Debye-Huckel model is not working perfectly, which I had previously overlooked!

Thanks again and best regards,

Frank

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...