stick_ball (boolean, default: off) controls whether or not PyMOL draws a ball (a sphere) at each end of the stick representation.
stick_ball_ratio (float, default: 1.0) controls the radius of the ball relative to that of the stick
stick_color (color, default: -1) contols the color of the stick representation. Atom color are used by default.
stick_fixed_radius (boolean, default: off) when the valence setting is enabled, this setting controls whether or not valence bonds are shown using cylinders of fixed or variable radius.
stick_nub (float, default: 0.7) controls the size of the cone placed on the end of cylinders.
stick_overlap (float, default: 0.2) control how far stick cylinders are extended beyond atom coordinates.
stick_quality (integer, default: 8) controls how many facets are used in representing the cylinders.
stick_radius (float, default: 0.25) controls the radius of the cylinder.
stick_transparency (float, default: 0.0) controls transparency of the stick representation.
stick_valence_scale (float, default: 1.0) controls the radius of the invisible cylinder within which bond valences are shown relative to the stick radius.