γ-Independent through-space hetero-nuclear correlation between spin-1/2 and quadrupolar nuclei in solids

Na7(AlP2O7)4PO4: F1 slices observed for P1, which presents the largest CSA = 27.5 kHz at 18.8 T and νR = 20 kHz with HMQC-D-SFAM1 and HUQC with R1023, R1653, R1452 and R3 recoupling. One observes very large differences in sensitivity, with HUQC-R1653 providing the largest S/N.190