********************************************************************* ********************************************************************* PTGIBBS- an EXCELTM Visual Basic program for computing and visualizing thermodynamic functions and equilibria of rock-forming minerals by A.Brandelik* & H.J. Massonne Institut für Mineralogie und Kristallchemie, Universität Stuttgart, Azenbergstr. 18, D-70174 Stuttgart, Germany * E-mail: andreas.brandelik@loop.de ********************************************************************* ********************************************************************* System requirements: --------------------- PTGIBBS requires complete Microsoft EXCELTM installation (version 8.0 or version 9.0) on an IBM-compatible personal computer. The minimum system requirements are a Pentium III 1000 Mhz processor (or equivalent) and 128 RAM memory. For a good performance a minimum screen resolution of 1024 x 768 is recommended. Important: ----------- To use PTGIBBS, the Excel Solver package must be installed on your system and Excel must be able to trust add-ins and templates. To avoid error messages based on solver incompatibilities, please follow these steps: 1) Open a new Excel-Workbook. 2) See the Tools Menu in Excel: if Solver is not installed, open the Tools/Add-ins menu; if Solver is missing, run the Office Setup program with the Add/Remove option, and install the Solver add-in. Read also the Microsoft documentations. 3) Modify security configurations Excel 97-Users: Click on menu item Tools > Options and then select the General tab and disable the Macro virus protection. Click OK. Excel 2000-Users: On the Tools menu, point to Macro and click Security. In the Security dialog box, click Low to change your macro security level and confirm with OK. Then click the Trusted Sources tab. Click to select the Trust all installed add-ins and templates check box. Click OK. Excel XP,2002,2003-Users: (PTGIBBS should also work with these versions) On the Tools menu, point to Macro and click Security. In the Security dialog box, click Low to change your macro security level. Click OK. Then click the Trusted Sources tab. Click to select the Trust all installed add-ins and templates check box and the Trust Access to Visual Basic Project check box. Click OK. 4) Close the opened Workbook and then run PTGIBBS. 5) After starting PTGIBBS for the first time, a VBAProject Password message box appears. Do not enter a password, only click on the Cancel button. 6) Click on solver (Tools menu). The solver window should now be displayed. Then close solver, by clicking on the button 'close'. 7) Then save the PTGIBBS workbook (name of the workbook can be changed). First use: ------------- After starting PTGIBBS the worksheet "Input" is automatically activated. In this worksheet mineral equilibria can be entered for computation. Three command bars appear in the upper portion of the screen as separate windows (command bars).They allow a simple navigation in the workbook and the start of different computation routines. 1. Example The routine "Calculate 3D" enables the display of diverse thermodynamic data of a selected phase as a function of P and T in a chart. No input within the range of the worksheet "Input" is necessary. After clicking on the control button "Calculate 3D" in the command bar "PTGIBBS CALCULATION" select a phase and a function in the opening dialogue (The P-T range can also be defined).The result will appear by clicking on the button "Create 3D plot". The spacial orientation of the chart can easily be changed by means of the scroll bars. By clicking on the button "Copy 3D data", the computed data are copied to the clipboard. You can reach the worksheet "Input" after computation, by closing the control dialogue (window "3D-Functions") and clicking on the control button "RETURN" in the command bar. 2. Example By clicking on the button "LOAD EXAMPLE" in the command bar ("SHEET CONTROL") input examples can be initialized in order to view the input structure. After loading example 4 click on the control button "Calculate equilibria" in the command bar "PTGIBBS CALCULATION". After starting the routine "Calculate equilibria" the button "SELECT ALL" has to be clicked in the opening dialogue. In the next dialogue, the P-T range for the computation can be defined. After calculation, the result is automatically displayed in the worksheet "PT_PLOT". An ActiveX list box is located at the top of the worksheet "PT_PLOT" listing the equations of the calculated reactions. By selecting a reaction there, the corresponding curve is automatically assigned in the chart (or vice versa). Additional procedures can be run by clicking on one of several control buttons arranged in the command bar. By means of an interactively operating system, it is possible, for example, to calculate the intersection between two curves, to display only selected curves, or to save the results of the calculation in a new workbook. You can reach the worksheet "Input" after computation, by clicking on the control button "RETURN" in the command bar.