Applicable for space groups is a rotation by 360°/ n about an axis, combined with a translation along the axis by a multiple of the distance of the translational symmetry, divided by n. This multiple is indicated by a subscript. So, 6 3 is a rotation of 60° combined with a translation of 1/2 of the lattice vector, implying that there is also 3-fold rotational symmetry about this axis. The possibilities are 2 1, 3 1, 4 1, 4 2, 6 1, 6 2, and 6 3, and the enantiomorphous 3 2, 4 3, 6 4, and 6 5. Considering a screw axis n m, if g is the greatest common divisor of n and m, then there is also a g -fold rotation axis. When n / g screw operations have been performed, the displacement will be m / g, which since it is a whole number means one has moved to an equivalent point in the lattice, while carrying out a rotation by 360°/ g. So 4 2, 6 2 and 6 4 create two-fold rotation axes, while 6 3 creates a three-fold axis.