Package: viewmol Followup-For: Bug #938774 For those following the plight of viewmol, avogadro may be your best substitute. Its molecule building is not quite as intuitive as viewmol but works well enough once you catch the rhythm of it (hold and drag the mouse button to add a new atom bonded to an existing atom).
avogadro also has the nice feature of energy minimisation for geometry optimisation (available from 1.93.0+git20200509.e169315-1), which viewmol never provided. avogadro can also generate input files for molecular dynamics computations.
