Editors' reviewThough this is a highly specialized and useful piece of software, its design and speed aren't exactly 21st century. PiSystems is designed for scientists and advanced chemistry students to help calculate the electronic spectra and colors of organic molecules. This is a large program that takes a while to download, and, once it's loaded, installation is slow. The interface, though not visually stimulating, isn't well-designed, either. During testing we noticed there is no way to scroll or zoom into displayed molecules; what's more, windows often stack up on top of each other, making it a bit of a digging exercise to find a display. Excel-like tables display most chemical data. The program toolbar offers plenty of mouse-over hints on discovering the function of each button. To draw a molecule, you must open a "molecule input" window (from the taskbar); once your sketch is done, apply the "idealize" feature. Calculations are rapid and the program allows for plenty of input or changes. The trial version allows for 20 uses, which may be of limited use for small projects.
This is the fastest, most reliable, and most user-friendly quantum-chemical program for the calculation of electronic spectra and colors of organic molecules as well as for support of synthetic science. A tour is available on the Web site, and special prices are available for educational use.