Since we compute this one-mode density matrix during the solution of the equations of motion for many wave functions anyway, it is simple to use this to compute the one-mode densities. If the one-mode density matrix has been diagonalized, the one-mode density of mode m is simply obtained as the norm square of each modal, weighted by the occupation number ω m r m (t) = D m r m r m (t). However, the density matrix is in general not diagonal and the modal density is obtained by squaring all combinations of modals in m and weighing them with the corresponding entry of the density matrix.