Table 2.

P=O_I bond lengths relative to the two non-bridging oxygen atoms O₁, O₂, and the 〈O=P=O〉 bond angle as obtained from the first-principles relaxation of model M3-A [Fig. 1(c)] by using LDA (PZ), GGA (PBE) and hybrid (PBE0) functionals.

	P=O1 (Å)	P=O2 (Å)	〈O=P=O〉 (deg.)
PZ	1.466	1.454	123.33
PBE	1.494	1.476	125.41
PBE0	1.477	1.464	125.56