ccRepo; a repository of correlation consistent basis sets.
Producing isodensity surfaces colour-coded with the electrostatic potential.
PlotBand; a simple Python script for plotting UV/Vis spectra.
geomConvert; Robert's utility for converting between Cartesian and Z-matrix geometries.
Libecpint; Robert's library for calculating integrals over ECPs.
Ab initio software
Molpro quantum chemistry package. This is the software package we use for most of our investigations, it has particular strengths in multireference calculations, explicitly correlated wavefunctions and local electron correlation.
Gaussian. A general electronic structure package that is user-friendly and is particularly good at geometry optimisations. Some might call it the industry-standard.
Turbomole. Again, a pretty general package, but it's strengths are generally in very fast DFT calculations. We also make extensive use of its ability to optimise basis sets for density fitting in MP2 calculations.
Gnuplot. A (free) command-line driven graphing utility. We use it to inspect potential energy surfaces.
DataGraph. A Mac based graphing application. It's easy to control and produces some very nice results with a minimum of effort.
Homebrew. An open-source package manager for the Mac. Makes it easy to install the utilities you might be familiar with from Linux.
VMD. Visual molecular dynamics is a visualiser for many different chemistry and biology programs. Although the name suggests it is used for MD calculations, it can produce some great images from time indepedent calculations too.