I am trying to display Molecular Electrostatic Potential surfaces, but nothing seems to happen after I click on the Show Surface button.
This particular surface can take a long time to display, so you may just need to wait a bit longer. The amount of time required to finally display the surface is dependant on the size of the model and the speed of the computer. The faster the computer, the faster the surface will display.
Calculating this surface for a benzene ring took 4 minutes on a Pentium III, 550 MHz PC with 128 Mb RAM.