Gaussian
A licensed electronic-structure package used for molecular energies, structures, vibrational calculations and related quantum-chemical properties.
Where it fits
Molecular calculation workflows supported by institutional Gaussian installations.
Limits and practical considerations
Platform, revision and parallel/GPU support must be checked against the official compatibility documents.
Licensing and access
Proprietary paid licensing; source access does not mean open source. GaussView and Linda may require separate licences.
Official GaussView guide and Gaussian setup