The modern theory of polarization recasts the expression for the expectation value of the position operator into a Berry phase of the cell-periodic parts of the Bloch functions. This approach abandons the notion of a completely unique value for the dipole moment, recognizing instead that the latter is determined modulo a so-called quantum of polarization. In this work, we employ large supercells for the computation of IR and Raman intensities. For large supercells, an evaluation only at the Γ-point is justified, for which the Berry phase dipole expression reads: