The new Li-Si-P ternary phase compounds Li₈SiP₄ and Li₂SiP₂ are the starting point of a large compound class. Both compounds form structures based on SiP4 tetrahedral building blocks and reveal a significant lithium ion mobility. The compounds were characterized by XRD and solid-state NMR, and Li ion mobility was investigated by impedance and temperature-dependent NMR spectroscopy.

See paper:

Lithium Ion Mobility in Lithium Phosphidosilicates: Crystal Structure, ⁷Li, ²⁹Si, and ³¹P MAS NMR Spectroscopy, and Impedance Spectroscopy of Li₈SiP₄ and Li₂SiP₂

L. Toffoletti, H. Kirchhain, J. Landesfeind, W. Klein,  L. van Wüllen, H. A. Gasteiger, T. F. Fässler, Chem. Eur. J. 2016 on-line (DOI: 10.1002/chem.201602903)