Fig. 4: DFT-calculated ³¹P ssNMR spectra of 4 Ni₂P slabs with different terminating surfaces.

NMR spectra from surfaces are in orange/green color, whereas blue color spectral contribution is from the bulk-like interior. The total NMR spectra are shown with dotted lines in gray color. The superimposed orange/olive and gray color lines indicate the calculated isotropic resonances (not including lineshape effects) of the P(1) and P(2) sites, respectively. a ³¹P DFT-calculated NMR spectrum of a Ni₂P slab with (0001-A) termination (super-cell with 50 atoms). b ³¹P DFT NMR spectrum of Ni₂P with (0001-B) termination (49 atoms). c ³¹P DFT NMR spectrum of Ni₂P with \(\left(0001-{\rm{A}}-{\rm{P}}\right)\) termination (52 atoms). The dark gray colored bar represents the isotropic resonances of the two surface P adatoms (again with no lineshape effects). d ³¹P DFT NMR spectrum of Ni₂P with \((10\bar{1}0)\) termination (54 atoms). e The DFT-calculated electron diffraction patterns (EDP) of the (0001-A) and \((10\bar{1}0)\) terminating slabs, which are the two most common facets in the Ni₂P nanoparticles. f Schematic presentation of Ni₂P nanoparticles in the P-excess limit, with the (0001) (red) and the \((10\bar{1}0)\) (green) facets terminations¹⁷.