For water in the C2v point group, the symmetric stretch corresponds to the A1 irreducible representation and the asymmetric stretch corresponds to the B1 irreducible representation for the coordinate system shown in Figure . The corresponding elements of the molecular hyperpolarizability are , and for the symmetric stretch and and for the asymmetric stretch. In a uniaxial system of C2v molecules, following equation 3, the chiral SFG response is given by 9, 12, 13, 15, 21