lcrossey Posted April 15 Share Posted April 15 In a simple Zn speciation model (in ACT2) I am not seeing fields for Zn-hydroxide species as expected. No prob with Fe,Mn and others. Quote Link to comment Share on other sites More sharing options...
Jia Wang Posted April 15 Share Posted April 15 Hello, It is very difficult to say what the issue might be without seeing your input file. A common error is that the species of interest may not be included in the thermo dataset. In that case, you will need to switch to another dataset that contains the species reaction you want to draw the activity diagram for. Another common error is that more stable species may appear and you need to suppress these for species unstable species may appear. Please see section 2.3 for more information on Thermodynamic datasets of the GWB Essentials Guide. You can find examples using Act2 in chapter 5 in the same guide. If this doesn't help and you would like someone to take a closer look, please attach your input file and thermodynamic dataset, and provide more context on what you are trying to create. Hope this helps, Jia Wang Aqueous Solutions LLC Quote Link to comment Share on other sites More sharing options...
lcrossey Posted April 17 Author Share Posted April 17 Thank you for responding Jia! I am attaching a simple input file to generate an EH-pH diagram for Zinc. I have an updated version and am using the default database. I am not seeing any Zn-hydroxide aqueous species that I expect at higher pH. I have no problem with Fe or Mn, for example. I have more complex chemistry to explore planned, but until I understand why there are no Zn-hydroxide species, I feel I cannot rely on this output. The Zn-hydroxide species do not even show up in the swap option as is the case for Fe, Mn, etc. If they are missing in the standard database (and I have seen publications referencing these species in the LLNL database, I would appreciate help in locating a database that does include them. Thanks again for any thoughts on this. Zn_simple.ac2 Quote Link to comment Share on other sites More sharing options...
Jia Wang Posted April 17 Share Posted April 17 Hello, Thank you for attaching your input file. The best way to see the reactions in a thermodynamic dataset loaded into your current calculation is to go to the "File" menu -> "View" -> click on the file with the extension .tdat or .dat to open in the TEdit application. You can filter on the element Zn and see all species containing Zn in its reaction. You can also use TEdit to edit datasets to add reactions from literature. For more information on using TEdit, please refer to chapter 9 in the GWB Essentials Guide. The default thermo dataset, thermo.tdat, doesn't contain any Zn-hydroxide species. An expanded version of the LLNL database, thermo.com.V8.R6+.tdat, is included in the software installation. Please see section 2.3 Thermodynamic datasets in the same guide for more information on datasets installed with the software. Hope this helps, Jia Quote Link to comment Share on other sites More sharing options...
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