In both the DVR and the discrete representation a discrete Hilbert space is employed. In the Fourier representation a uniform grid spacing is used to obtain a finite Fourier series. The quadrature weight is the grid spacing (trapezoidal rule). This quadrature is of comparable accuracy to the Gaussian quadrature employed in the DVR representation.
The Fourier method scales as
as opposed to an
scaling of the DVR method. The DVR, however, provides the opportunity
of choosing the basis functions
according to the
physical system so their number can be kept rather small (e.g. LCAO).