chemsk

ACD/ChemSketch is a molecular modeling program used to create and modify images of chemical structures. Also, there is a software that allows molecules and molecular models displayed in two and three dimensions, to understand the structure of chemical bonds and the nature of the functional groups. (Summary from the program web page.)

The official web page: https://www.acdlabs.com/resources/freeware/chemsketch/index.php

Typical use

$ module add chemsk
$ chemsk