The EMT potential is included in the ASE package in order to have a simple calculator that can be used for quick demonstrations and tests.
Warning
If you want to do a real application using EMT, you should used the much more efficient implementation in the ASAP calculator.
Right now, the only supported elements are: H, C, N, O, Al, Ni, Cu, Pd, Ag, Pt and Au. The EMT parameters for the metals are quite realistic for many purposes, whereas the H, C, N and O parameters are just for fun!