# Creating Molecule Types

To create a molecule type the user must first create a molecule within the Editor Window, optionally name it, and specify its allowed states. BioNetGen names all molecules and their components by default with the letter C. An unlimited number of molecules may exist within the Editor Window that share the same name, however upon moving the molecule and registering it within the Molecule Types Palette Window, the user will be prompted for an alternate name to ensure no name clashes exist.

A molecule can be created by placing components with in a container. Components and containers correspond to domains within a molecule. There is no limit to the number of components that may be added to a container, nor is there a required order of creation. Components may be created first followed by a container, or a container may be created first and components added. In either case the size of a container is flexible and may be extended by dragging the resize handles to the desired extent.