Update package/MDAnalysis/core/groups.py

Co-authored-by: Rocco Meli <[email protected]>

package/MDAnalysis/core/groups.py

@@ -3111,7 +3111,7 @@ def select_atoms(self, sel, *othersel, periodic=True, rtol=1e-05,
                 radius 5, external radius 10 centered on the COG. In z, the
                 cylinder extends from 10 above the COG to 8 below. Positive
                 values for *zMin*, or negative ones for *zMax*, are allowed.
-            box *dimensions* *dN_min* *dN_max* *selection*
+            box *dimensions* *dN_min* *dN_max* [*dN_min* *dN_max*] [*dN_min* *dN_max*] *selection*
                 Select all atoms within a box region centered
                 on the center of geometry (COG) of a given selection.
                 *dimensions* Specifies which dimension(s) to apply