user@xubuntu2204:~$ sudo apt-get install avogadro [sudo] password for user: Reading package lists... Done Building dependency tree... Done Reading state information... Done The following additional packages will be installed: avogadro-utils cclib libaec0 libavogadro-data libavogadro2-1 libglew2.2 libhdf5-103-1 libsymspg1 libsz2 molequeue python3-cclib Suggested packages: cclib-data glew-utils The following NEW packages will be installed: avogadro avogadro-utils cclib libaec0 libavogadro-data libavogadro2-1 libglew2.2 libhdf5-103-1 libsymspg1 libsz2 molequeue python3-cclib 0 upgraded, 12 newly installed, 0 to remove and 6 not upgraded. Need to get 122 MB of archives. After this operation, 706 MB of additional disk space will be used. [...] user@xubuntu2204:~$ user@xubuntu2204:~$ sudo apt-get install openbabel Reading package lists... Done Building dependency tree... Done Reading state information... Done The following additional packages will be installed: libboost-iostreams1.74.0 libinchi1 libmaeparser1 libopenbabel7 The following NEW packages will be installed: libboost-iostreams1.74.0 libinchi1 libmaeparser1 libopenbabel7 openbabel 0 upgraded, 5 newly installed, 0 to remove and 6 not upgraded. Need to get 4.148 kB of archives. After this operation, 19,1 MB of additional disk space will be used. [...] user@xubuntu2204:~$ user@xubuntu2204:~$ obabel --version No input file or format spec or possibly a misplaced option. Most options must come after the input files. (-i -o -O -m can be anywhwere.) Open Babel 3.1.1 -- Feb 7 2022 -- 06:51:49 Usage: obabel [-i] [-o] -O [Options] Try -H option for more information. user@xubuntu2204:~$