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mixing two waters

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I am trying to use React to mix the two waters in the attached script. I can't seem to get a proper charge balance. I have tried to move the ion on which I balance my charge to every ion in my basis water and I keep getting the same error:

Residuals too large, 663-th iteration

Largest residual(s):

Resid Resid/Totmol Cbasis

Cl- 0.07619 1.38e+200 5.456e-202

I even tried adding other ions that weren't part of the original water, but I get the same error. How do I get my charge to balance? Thanks!

P5 at 365 days and recharge.rea

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Hi:

It looks like the low pH is the reason for non-convergence. If you try a slightly higher pH (3.5), the script runs fine.

Hope that helps,

Tom Meuzelaar

RockWare, Inc.

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Why does GWB force you to increase the pH to balance the reaction? Is there something in the GWB manual that explains this? What about other literature sources? Thanks!

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Hello:

This isn't necessarily an issue with charge balance. It could be that you've defined a system that is far from equilibrium, and thus has trouble converging. If the pH value is important, I recommend starting with 3.5, so the system initially converges, then sliding the pH (in the Reactants pane) down to 3.1, so that you have a stable chemistry.

Hope that helps,

Tom Meuzelaar

RockWare, Inc.

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