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Author Topic: Elements in species not tabulated or defined  (Read 593 times)

mbcomins

  • Contributor
  • Posts: 4
Elements in species not tabulated or defined
« on: November 08, 2020, 01:49:13 PM »
Hello,

I am building a database to model neodymium and citrate solubility and speciation as a function of pH. Strangely, I am getting the following errors:

WARNING: Unknown input, no keyword has been specified.
   NAMED_EXPRESSIONS
   SOLUTION_MASTER_SPECIES
   SIT
   SOLUTION_SPECIES
   PHASES
ERROR: Elements in species have not been tabulated, H.
ERROR: Reaction for species has not been defined, H.
ERROR: Calculations terminating due to input errors.

The reason this is strange is because I have indeed defined "H" in my database, including the formation reaction and logK. I have attached my database for review. Any tips as to where I might be going wrong would be hugely appreciated.
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dlparkhurst

  • Top Contributor
  • Posts: 2546
Re: Elements in species not tabulated or defined
« Reply #1 on: November 08, 2020, 03:48:59 PM »
The following equation is missing a plus sign after H+.

Code: [Select]
1.000Nd+3      + 1.000H+     2Cit-3     = NdH(Cit)2-2
     log_k    18.11     #14BRO/KRO

This reaction does not balance in charge. To balance, Nd(OH)4(Cit)4-13 is needed.

Code: [Select]
1.000Nd+3     - 4.000H+     + 4.000H2O     + 4.000Cit-3     = Nd(OH)4(Cit)4-7
     log_k    34.43     #81SVO/BOU

Finally, your definition of Cit(-4) is not correct, in part because the reaction doesn't balance. But more importantly, Cit(-4) represents a different valence state, which requires a reaction that contains e- or O2. If you really want a different redox state, then either of the following reactions would work, but you need an appropriate log K.

Code: [Select]
1.000Cit-3     + e-     = Cit-4
or
Cit-3 + 1/2H2O = 1/4O2 + H+ + Cit-4
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mbcomins

  • Contributor
  • Posts: 4
Re: Elements in species not tabulated or defined
« Reply #2 on: November 08, 2020, 09:21:41 PM »
I got it to work! Thank you so much for your help!
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