GEM-Selektor v.3: Frequently Asked Questions 

• Right-click on the first cell of data array field and, in the appearing menu, choose "Select Object", "Select Column", or "Select Row". Then right-click again on the same cell and select "Copy". Switch to Excel table, click on a cell and execute "Paste".
• You can also copy data from Excel to GEMS3 by doing a reverse: first mark and copy numbers in Excel and then go to GEMS3, right-click on the first cell of data object field, and select "Edit" "Paste" (or "Paste transposed"). Take care that there are enough rows and columns in the GEMS3 data object.

After the calculation of single chemical equilibrium, GEMS3 asks to "Accept" or "Discard". What does the program do when I press "Accept"? when I click "Discard"?

• Upon clicking "Accept" on the "Progress Dialog", GEMS3 will pack the calculated chemical speciation and store it as a "SysEq" record in the modelling project database. If a record with such key already exists, it will be updated.
  
• If "Discard" is clicked, the SysEq record will not be created or updated, i.e. the calculated speciation will be lost.

• Switch to "Thermodynamic Database" mode, open "Predefined Compositions (Compos)" window, display there a record for air, and "clone" it under a different name (record key). Then change the addition of C and O (or CO2). Set cells "MasVol[0,0] and MasVol[0,6] to zeros, re-calculate the record and save it to database.
  
• Close the Compos window and open your process again.Click "Ok" on the appearing message about new Compos entry. Now you can use in any of your systems either of air compositions.
  

After I have excluded an independent component (element) in a single thermodynamic system, how can I switch it on again?

Adding a new aqueous complex or a new phase to the thermodynamic database, in which data fields I have to enter something and what? (e.g. what can I do if I only have log K?)

After entering a new record in the thermodynamic database in one modeling project, how can I use this record in different projects? If I entered more records, how can I create an additional database file?

How can I upgrade GEM-Selektor to the most recently released version? 

• Shut down GEMS program; backup test \projects folders, if you worked with them. We recommend also to backup the Resources\DB.default\ folder.
  
• Download the latest GEMS3 installer package for your desktop PC platform into a temporary files directory.  
• Execute the installer and select your existing GEMS directory as an installation directory.The GEMS3 installer will overwrite or add test projects directories, but it will not touch your work projects directories. 
• Restore your modified test projects directories, if any (allow overwriting files).
• Start GEMS3 using the desktop icon or a "Start menu" entry. 
  

How can I learn quickly to set up a system and calculate the equilibrium speciation using GEM-Selektor?

Download GEMS3 package and install it, as described on the distribution page. Start GEMS3,and execute "Help" "Tutorial" menu command to open the Help window with the Tutorial page. Do not close Help window and run the code in parallel with reading the Tutorial.

 

Send us an e-mail to gems2.support@psi.ch. There, describe the problem briefly. Send us also (as an e-mail attachment) your (zipped) modeling project directory with comments indicating which database records have problems. In this case, your bug report will have a good chance to appear soon in the List of corrections.