Usage:
focus [ atom-spec ]

Focus adjusts the view and center of rotation based on atoms, bonds, and/or ribbon segments that are displayed (possibly including items that are invisible) If atoms are specified, only those both specified and displayed are considered in making the adjustments. Focusing consists of

1. adjusting the view to include item(s) both specified and displayed (like the command window)
2. making the center of the bounding box of the item(s) the center of rotation (like the command cofr)

See also: center, cofr, set, setcom, window