Avogadro 1 is not under active development, the repository was archived in September 2021. Development of Avogadro 2 is being done at https://github.com/openchemistry/avogadrolibs. Avogadro is an advanced molecular editor designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science, and related areas.
Avogadro cannot view the vibrational frequencies of a Gaussian16 output properly when the output employs frozen atoms