for example, water (h2o) which has the c2v symmetry described above. the 2"p"x orbital of oxygen is oriented perpendicular to the plane of the molecule and switches sign with a c2 and a σv'(yz) operation, but remains unchanged with the other two operations (obviously, the character for the identity operation is always +1). this orbital's character set is thus {1, -1, 1, -1}, corresponding to the b1 irreducible representation. similarly, the 2"p"z orbital is seen to have the symmetry of the a1 irreducible representation, 2"p"y b2, and the 3"d"xy orbital a2. these assignments and others are in the rightmost two columns of the table.