Because GaussView 5 is proprietary, you should verify if you can access it legally through official channels:
: Seamlessly sets up, launches, and monitors calculations for the Gaussian quantum chemistry suite, including support for Gaussian 09 methods. 3D Visualization
GaussView 5 is an older version. Some users prefer it over newer releases (like GaussView 6) because it matches the specific version of Gaussian their lab is running. The Risks of "Free" Downloads
(e.g., geometry optimizations, frequency analysis) without manually writing input files.
Downloading GaussView 5 for free as a "portable" version is not possible through legal or official channels
: Renders molecular orbitals, electron densities, and electrostatic potential maps directly from calculation results. PDB Support