Supporting Information for: A Simple Coulombic Model for 31 P NMR Spectra of Cluster-Encapsulated Phosphorous Atoms Mark Baranov †* , Tal Tubul † , Yohai Azulai † and Ira A. Weinstock †* † Department of Chemistry and the Ilse Katz Institute for Nanoscale Science & Technology, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel Contents Table S1. Compounds for which a correlation was initially observed Table S2. Parameters used for modeling (PO 4 )M 12 skeletal structures Table S3. Calculated F values and experimental 31 P NMR chemical-shift values of P atoms in Keggin-derived heteropolytungstates Table S4. Calculated F values and experimental 31 P NMR chemical-shift values of P atoms in Keggin-derived heteropolymolybdates Table S5. Calculated F values and experimental 31 P NMR chemical-shift values of P atoms in Keggin-derived heteropolytungstatomolybdates S1. Error criteria used for the model S2. Sample calculation of F for the α-[PW 12 O 40 ] 3- anion Table S6. Crystal radii of the elements that are modeled in the example given in S1 Figure S1. P-31 NMR spectra of α-[PGaW 11 O 39 ] 4- , α-[PAlW 11 O 39 ] 4- and α-[PInW 11 O 39 ] 4-