Residuals too large

[Karen Johannesson]

Dear All,

I am trying to figure out why an X1t script I have built will run with an initial SCM but not a nearly identical one, which returns the error  Solving for composition of fluid "inlet". Residuals too large.... The only difference between the two SCMs in that  FeOH_REE_Carrizo_2005.sdat has much lower weak and strong site concentrations than FeOH_REE_Carrizo_2005b.sdat. I think the very low surface site concentrations on the first SCM are probably not correct. Nevertheless, the models runs fine with "*_2005.sdat, but returns the residuals too large error when I use "*_2005b.sdat". I have tried to balance the simulation on Na+, Ca++, and Cl-, and have even #-out the "balance on Cl-" command in the script. I tried to turn off the balance by right clicking on the concentration units as suggested in a GWB forum post I read on line, but that function doesn't work on my computer. I run GWB on a Mac using Parallels, so maybe that is why the right clicking doesn't work. That said, right clicking on any of the other software I use through Parallels (SigmaPlot, etc.) works fine. 

I should mention that this "Chemical_Weathering_5o1_REE.x1t" is one I am testing at the moment, so there are lots of comments and commands I have commented out using the # symbol.  Those will eventually be cleaned up.

Best wishes,

Karen

 

Chemical_Weathering_5o1_REE.x1t thermo_REE_ionx.tdat FeOH_REE_Carrizo_2005.sdat FeOH_REE_Carrizo_2005b.sdat

[Karen Johannesson]

I was hoping someone at the forum might have some suggestions about how I can proceed. I posted this almost a month ago.