dft_input
dft_misc_input
dft_symmcorr_input
dft_symmpar_input
dft_parproj_input
dft_bands_input
dft_transp_input
dft_contours_input
dft_update
Calculate H(k) for a group by applying the projectors P to the eigenvalues eps.
H_ij(k) = sum_l P*_il eps_l P_lj