Calculating a Potential Diagram with Different Pressure

It is possible to modify both the calculation and the plotted diagram that the POTENTIAL module generates in the POLY and POST modules. You can do this by opening a POLY3-file with the results from a POTENTIAL module calculation in either POLY or POST. You can modify the calculation in the same way that you can modify any ordinary mapping calculation or phase diagram. For example, this is useful for calculating a potential diagram at a pressure other than 1 bar.

POLY Module Commands

You must have calculated a potential diagram already, and have the saved POLY3-file available.

  1. Use GOTO_MODULE and enter POLY.

  2. Use READ followed by the name of the POLY3 file that contains the results of the potential diagram calculation that you want to modify.

    A reminder that Linux and Mac are case sensitive; when applicable ensure you enter file extensions with capital letters.

  3. This opens the workspace file and loads the previous settings and results. The activities of the two gaseous species is now part of the conditions, and these conditions are set as the mapping variables.

  4. Use SET_CONDITION to specify the pressure under which you want the potential diagram to be calculated. For example, to set the pressure to 1000 bar, enter:

    SET_CONDITION P=1e8

  5. Use COMPUTE_EQUILIBRIUM to compute the initial equilibrium.

    You may also want to use ADD_INITIAL_EQUILIBRIUM to calculate some additional equilibria that the mapping calculations are based on.

  6. Use MAP to perform the mapping calculations.
  7. Use GOTO_MODULE and enter POST to set conditions for visualization and to plot the diagram.