“center” translates the window, the clipping slab, and the origin to a point centered within the atom selection.

center [ selection [, state [, origin [, animate ]]]]

selection = string: selection-expression or name pattern (default: “all”).

state = 0 (default) use all coordinate states

state = -1 use only coordinates for the current state

state > 0 use coordinates for a specific state

origin = 1 (default) move the origin

origin = 0 leave the origin unchanged

chain chain B 
center 145/ 

origin | orient | zoom | cmd.center | commands