Yes, a typo.
GIG64 where it does not work
francesco@gig64:~$ echo $PATH
opt/molden:/opt/NAMD_2.12_Linux-x86_64-multicore:/opt/anaconda2/bin:/opt/MGLTools-1.5.6/bin:/opt/vina_1_1_2_linux_x86/bin
pt/molden:/opt/NAMD_2.12_Linux-x86_64-multicore:/opt/anaconda2/bin:/opt/MGLTools-1.5.6/bin:/opt/vina_1_1_2_linux_x86/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/opt/UCSF/Chimera64-1.11.2/bin:/opt/VMD:/opt/vina_1_1_2_linux_x86/bin/vina:/opt/NAMD_2.12_Linux-x86_64-multicore/namd2:/opt/UCSF/Chimera64-1.11.2/bin:/opt/VMD:/opt/vina_1_1_2_linux_x86/bin/vina:/opt/NAMD_2.12_Linux-x86_64-multicore/namd2
francesco@gig64:~$ which molden
francesco@gig64:~$ which gmolden
francesco@gig64:~$
i.e., nothing from "which"
VAIO where it works (if anything, it is unclear why the PATH variable is reated for molden, while there is a single instance of that and only .bashrc was used, no .profile ; the same issue for "mopac")
francesco@vaio64:~$ echo $PATH
/opt/molden:/opt/mopac:/usr/local/lib/plugins/LINUXAMD64/bin/catdcd5.2:/opt/NAMD_Git-2018-11-27_Linux-x86_64-multicore:/opt/anaconda2/bin:/opt/MGLTools-1.5.6/bin:/opt/vina_1_1_2_linux_x86/bin:/opt/molden:/opt/mopac:/usr/local/lib/plugins/LINUXAMD64/bin/catdcd5.2:/opt/NAMD_Git-2018-11-27_Linux-x86_64-multicore:/opt/anaconda2/bin:/opt/MGLTools-1.5.6/bin:/opt/vina_1_1_2_linux_x86/bin:/opt/molden:/opt/mopac:/usr/local/lib/plugins/LINUXAMD64/bin/catdcd5.2:/opt/NAMD_Git-2018-11-27_Linux-x86_64-multicore:/opt/anaconda2/bin:/opt/MGLTools-1.5.6/bin:/opt/vina_1_1_2_linux_x86/bin:/opt/molden:/home/francesco/softw/MSMS:/opt/mopac:/usr/local/lib/plugins/LINUXAMD64/bin/catdcd5.2:/opt/NAMD_Git-2018-11-27_Linux-x86_64-multicore:/opt/anaconda2/bin:/opt/MGLTools-1.5.6/bin:/opt/vina_1_1_2_linux_x86/bin:/opt/molden:/home/francesco/softw/MSMS:/opt/mopac:/usr/local/lib/plugins/LINUXAMD64/bin/catdcd5.2:/opt/NAMD_Git-2018-11-27_Linux-x86_64-multicore:/opt/anaconda2/bin:/opt/MGLTools-1.5.6/bin:/opt/vina_1_1_2_linux_x86/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/sbin:/usr/sbin:usr/local/sbin:/opt/UCSF/Chimera64-1.13.1rc/bin:/opt/vina_1_1_2_linux_x86/bin/vina:/opt/namd_Git-2018-11-27_Linux-x86_64-multicore/namd2:/opt/UCSF/Chimera64-1.13.1rc/bin:/opt/vina_1_1_2_linux_x86/bin/vina:/opt/namd_Git-2018-11-27_Linux-x86_64-multicore/namd2:/opt/UCSF/Chimera64-1.13.1rc/bin:/opt/vina_1_1_2_linux_x86/bin/vina:/opt/namd_Git-2018-11-27_Linux-x86_64-multicore/namd2:/opt/UCSF/Chimera64-1.13.1rc/bin:/opt/vina_1_1_2_linux_x86/bin/vina:/opt/namd_Git-2018-11-27_Linux-x86_64-multicore/namd2:/opt/UCSF/Chimera64-1.13.1rc/bin:/opt/vina_1_1_2_linux_x86/bin/vina:/opt/namd_Git-2018-11-27_Linux-x86_64-multicore/namd2
francesco@vaio64:~$
francesco@vaio64:~$ which molden
/opt/molden/molden
francesco@vaio64:~$ which gmolden
/opt/molden/gmolden
francesco@vaio64:~$