When the "Rubber band" item of the "Structure" menu is unchecked, a bond is constructed by clicking the mouse button on each end of the bond. A multiple bond is constructed by clicking on each end of the existing bond. Alternatively, if "Rubber band" is selected from the "Structure" menu, bonds are created with a click and drag.
If the "Fixed bond length" item of the "Structure menu" is checked all bonds will be drawn with the same default bond length. The default bond length is defined by choosing "Set default length..." from the Structure menu.
The size and orientation of a structure may be altered at any time by choosing the appropriate item from the "Structure" menu. Using "Smooth bonds" may improve the appearance of a poorly drawn structure.
Adding heteroatoms:
Heteroatoms are added to the structure by choosing an atom from the palette and then clicking on a node, the atom will be transferred to the structure. Hold the option key down to continually add the same atom to a structure. To remove or alter an existing atom, replace it with another choice from the palette.
