Using the mouse

 

main button
(left)

middle button

secondary button
(right)

Open Jmol menu

Ctrl. + click
or click on 'Jmol' logo
  Click

Rotate around X,Y

drag    

Move along X,Y
(= translate)

Shift + double-click and drag Double-click and drag Ctrl. + drag
you can click either on the molecule or away from it

Restore and center

Shift + double-click Double-click  
you must click away from the molecule

Rotate around Z

Shift + drag horizontally Drag horizontally Shift + drag horizontally
(may fail on Mac)

Zoom in, zoom out

Shift + drag vertically Drag vertically  
or use mouse wheel
Only work after a previous slab on command:

Slab
from the front

Ctrl.+Shift + drag (vertically) *    

Slab
from the rear

Ctrl.+Shift + double-click and drag (vertically) *    

Shift the slab
(keeping constant thickness)

Alt.+Ctrl.+Shift + drag (vertically) *    
* if it fails on a Mac, try clicking first, then hold the key(s), then drag