ACEM/JCSTEM
This software is developed by Professor Earl Kirkland of Cornell University. This code is freely available as an interactive Java applet and as standalone code written in C/C++. The Java applet is ideal for a quick introduction, with the caveat (and disclaimer) that the results are not accurate. The ACEM code accompanies an excellent text of the same name by Kirkland which describes several techniques for simulating electron micrographs (including multislice) in detail. Unfortunately, the main C/C++ routines use a command line interface (CLI) and thus may not be appropriate for beginners. http://people.ccmr.cornell.edu/~kirkland/
Read more about this topic: Multislice