and outer Ti environments in Ti3AlC2 could be assigned from the overlapped spectrum (Figure ) by considering that the CQ values for the outer/inner metal sites are expected to differ by an order-of-magnitude (c.f. 93 Nb in Nb4AlC3), and by using the fixed relationships between the nuclear properties of 47/49 Ti. The quadrupolar parameters of the two titanium sites for both nuclei are given in Table : since the frequency separation and ratio of the quadrupolar coupling constants for the Ti and Ti signals are fixed by their respective nuclear properties, there are fewer independent parameters than it might seem, and the simultaneous agreement of both signals with the measured spectrum affords a high confidence in the NMR parameters. As also observed for the Nb MAX phases (Table ), the Ti sites exhibit axial quadrupolar tensors, consistent with the crystallographic symmetry, while the inner site has a modest CQ relative to the outer site. a The 47 Ti shifts are referenced to Ti and as such are 266 ppm less than the corresponding Ti shift, rather than equal.