title: Comment on the reference compound for chemical shift and Knight shift determination of (209)Bi nuclei.
abstract: Several groups exploring the (209)Bi NMR in solids, including usual insulators, metallic and magnetic materials and recently diamagnetic topological materials, use different standards (usually old and invalid) for chemical shift (Knight shift) determination, ignoring IUPAC recommendations. As a consequence the published shift values exhibit considerable differences (up to 17,500 ppm).
authors.affiliation: W. Trzebiatowski Institute for Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław, Poland. Electronic address: B.Nowak@int.pan.wroc.pl.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Nowak
keywords: (209)Bi NMR; Chemical shifts (Knight shifts) referencing; Solid state; Topologically nontrivial materials