CPK

`CPK' is a combination of both `Bonds' and `VDW' in that it draws the atoms as spheres and the bonds as cylinders. The resolution and radius can be modified independently. The size of the sphere drawn in CPK mode is by default the scaled-down VDW radius, but this scaling-factor can be changed by adjusting the Sphere Scale parameter. Since a sphere is drawn for each atom, it will always be slower than the `VDW' option, but we will work on performance for future versions. If the values for a sphere or bond attribute are too small, then those objects will not be drawn.