Herein, an advantage of the use of IDSCRF-over UFF-radii-based solute cavities in GIAO/DFT calculations is presented for the and especially NMR chemical shifts made for several bicyclic aromatic nitrogen heterocycles in CDCl3 solution treated within the classical IEF-PCM solvation scheme. Successful application of the IDSCRF-radii in the non 1:1 joint multinuclear H-1/C-13 and particularly H-1/C-13/N-15 correlations of the measured delta(H,C(,N)) values to those obtained theoretically is also documented for a series of test systems (-268 <= delta(N) <= 72 ppm). The experimentally yet unknown delta(N)'s were found in this way for the title compounds via a trinuclear eq 1 determined for an series of test systems (-268 <= delta(N) <= -72 ppm). The experimentally yet unknown delta(N)'s were found in this way for the title compounds via a trinuclear eq 1 determined for an optimally chosen value of the multiplication factor of initial raw delta(H) data (m(H) = 10). Such a simultaneous analysis of the delta(H,C(,N)) data is proposed as a novel method to study the solution structure of the other similar conformationally homogeneous (bio)organic compounds. The issue of small spurious imaginary vibrational frequencies computed for a few molecular systems using the Gaussian 09 default UFF-radii is briefly considered as well.