There are more chemical compounds than there are words in English, and molecular calculations are among the largest and most complex in science. Chemistry software has steadily improved from the first ChemDraw, which could simply draw 2-D structures, to the current ChemOffice Ultra 2001, which can simulate just about every task in modern chemical research. What's more, ChemOffice joins the Internet age with integrated Web searching.
The three parts of ChemOffice are ChemDraw, Chem3D, and ChemFinder. ChemDraw is a chemical CAD program; you assemble molecules from a palette of prefab parts. The Ultra version of ChemDraw gives you 3D models from your drawing, simulates spectra (see "More Than Drawing"), and will call up commercial sources for the chemical you've drawn just by clicking a link. Chem3D is a modeling program with quantum-chemistry options (MM2, MOPAC) for turning a 2-D drawing into a 3-D structure. It works directly with Iowa State's free quantum-chemistry program GAMESS.
Finally, ChemFinder is a chemical database. Chemistry databases allow you to search not only for a word but also for drawings of a compound, fragments of structures, or chemical properties. ChemFinder includes a translator for importing data from files formatted for Molecular Design Limited databases (ISIS, MACCS, REACCS). Adding access to minicomputer MDL databases has finally made ChemFinder competitive with UNIX desktop chemistry applications. CambridgeSoft also includes helpful notes for importing data from FileMaker.
There are plenty of useful new features. ChemDraw will now draw a structure from a systematic name, and a single click on a link starts a search for commercial suppliers of the compound you've drawn.
The biggest difference in Chem3D is not the software -- it's that Mac hardware is now fast enough to encourage chemists to routinely run MOPAC calculations on long lists of possibilities when looking over reaction mechanisms. ChemOffice is now optimized for the Velocity Engine in the G4 chip, and CambridgeSoft is working on support for dual processors. However, that new hardware prowess should encourage chemists to try out theprogram MacSpartan, a significantly more powerful quantum chemistry suite than Chem3D.
Too Many Choices
Some aspects of ChemOffice are problematic. The first is deciding what to buy -- nearly every product ships as part of a package. Chem3D Ultra ($899), for example, ships with ChemDraw Standard. Will that be good enough, or do you need ChemDraw Ultra instead, which includes modules for predicting spectra and chemical properties from molecular structures? Be prepared to while away a few hours puzzling out the dozens of software combinations and prices in the CambridgeSoft catalog.
Although it isn't CambridgeSoft's fault, Mac users of ChemOffice may feel underpowered compared to users with the Windows version. ChemOffice on the Mac can't work with the most popular molecular modeler, as there is no Mac version of Gaussian. ChemFinder also can't use the scads of CD-ROM chemical databases in Windows format -- you'll need you get ChemOffice WebServer (on a Windows NT server), so your Mac can access them as a client. ChemFinder for the Mac also lacks a Microsoft Excel interface, which means Mac users can't use CambridgeSoft's CombiChem software for creating combinatorial libraries.More Than Drawing: ChemDraw Ultra includes ChemNMR, which can simulate carbon-13 or proton NMR spectra for any compound you draw.