Comment on "Angstrom-scale probing of paramagnetic center location in nanodiamonds by 3 He NMR at low temperatures" by V. Kuzmin, K. Safiullin, G. Dolgorukov, A. Stanislavovas, E. Alakshin, T. Safin, B. Yavkin, S. Orlinskii, A. Kiiamov, M. Presnyakov, A. Klochkov and M. Tagirov, Phys. Chem. Chem. Phys., 2018, 20, 1476.

Kuzmin et al. reported on the application of the 3He NMR relaxometry technique to localization of intrinsic paramagnetic defects in detonation nanodiamond (DND) particles. We found some inconsistencies in the DND characterization, the model of paramagnetic defects' allocation used in that work as well as the estimation of distances between 3He NMR probes and paramagnetic defects, which question the results obtained.