The local structures and oxygen/fluorine ordering of Cdpy(4)NbOF(5) (py = C5H5N) and [pyH](2)[Cdpy(4)(NbOF5)(2)] have been investigated with F-19, Cd-113, and Nb-93 solid-state NMR spectroscopy. The Nb-93 magic-angle spinning (MAS) NMR spectra acquired at an ultrahigh magnetic field strength (19.6 T) and at ultrahigh spinning speeds (similar to43 kHz) of both compounds are dominated not only by the quadrupolar interaction but also by the chemical shielding (CS) interaction, consistent with highly asymmetric environments for niobium. A methodology is presented to extract the nuclear quadrupole coupling constant C-Q, the asymmetry parameter eta, and the isotropic chemical shift delta(iso) in the presence of a large chemical shift anisotropy (CSA). The CS tensor was then obtained from the simulations of the Nb-93 (I = 9/2) static NMR spectrum. The separations between the centerband of the central transition and sidebands of the +/-3/2 <----> +/-5/2 satellite transition in the Nb-93 MAS NMR spectra are sensitive to the value of C-Q(Nb-93), while the line shapes are mainly determined by 17 and the relative orientation between the electric field gradient (EFG) and CS tensors. Thus, simulations of the MAS NMR spectra provided additional constraints on the fitting of all these parameters. The Nb-93 MAS NMR spectra acquired at lower field and lower spinning speeds, where the spinning sidebands are not separated from the centerband, were also reproduced in the simulations. The following parameters were determined for the two compounds at room temperature: C-Q = 36.0(5)/33.2(5) MHz, eta = 0.50(5)/0.40(5), delta(iso)(Nb-93) = -1310(10)/-1320(10) ppm, Omega = 1000(20)/1100(20) pmm, kappa = 1.00(5)/0.8(1), alpha = 0(20)degrees/60(20)degrees, beta = 0(2)degrees/5(2)degrees, gamma = 0(20)degrees/0(20)degrees for Cdpy(4)NbOF(5)/[pyH](2)[Cdpy(4)(NbOF5)(2)], respectively. A very distorted multiplet in the solid-state F-19 MAS NMR spectra was observed, which arises from J-coupling [(1)J(Nb-93,F-19) = 362(2) and 350(5) Hz, for Cdpy(4)NbOF(5) and [pyH](2)[Cdpy(4)(NbOF5)(2)], respectively] and residual dipolar coupling between the F-19 and Nb-93 nuclei. Only one Cd-113 NMR resonance is observed for Cdpy(4)-NbOF5, which, together with the F-19 NMR, suggests that the O-substitution is not random. On the basis of the Cd-113 NMR, the NbOF5 octahedra are most likely oriented in opposite directions in different chains so as to allow the acentric NbOF5 octahedra to occupy a center of inversion in the crystal structure of this compound determined by X-ray diffraction (the "interchain" cancellation mechanism proposed by Heier et al., in J. Solid State Chem. 1997, 133, 576-579).