On the other hand, R spatial ( n ^ ^ , 360 ∘ ∘ ) = + 1 in all circumstances, because a 360° rotation of a spatial configuration is the same as no rotation at all. (This is different from a 360° rotation of the internal (spin) state of the particle, which might or might not be the same as no rotation at all.) In other words, the R spatial operators carry the structure of SO(3), while R and R internal carry the structure of SU(2).