If your institution lacks a license and the cost is prohibitive, consider these free/open-source alternatives that can perform many (though not all) of the same calculations:
Which of those would you like?
is the flagship computational chemistry software package developed by Gaussian, Inc. It is widely regarded as the industry standard for predicting molecular energies, geometries, vibrational frequencies, and numerous other properties using ab initio, density functional theory (DFT), and semi-empirical methods.
provide specific portals where students can download the installer and get a valid serial number. Purchasing a License:
Gaussian needs to know where its "scratch" directory is (where temporary calculation files are stored) and where the main executable is.
