KFMASH Grid w/AFM Topologies. AFM petrogenetic grid based on the thermodynamic model dataset SPaC (version 4/2000) developed originally by Spear and Cheney (1989). AFM topologies were calculated by Frank Spear at temperatures every 4°C and at pressures every 200 bars following the procedures of Spear (1998). Because there are many (5168) AFM files, wait 30 seconds after you load this page for the files to download. Then move your mouse over the PT diagram on the left to see how the AFM topology changes. Click on the PT diagram to stop the animation at a particular temperature and pressure. Click the Animate button (upper right) to resume the animation.