Table 1 Comparison between site populations (a.p.f.u), site scattering (s.s., a.p.f.u) and mean bond length (m.b.l., Å) values, derived from structural refinement and EPMA based recalculations. M.b.l. values for T sites in EPMA based recalculations were reported according to Oberti et al.²⁶.

Site

Population

s.s

m.b.l

m.b.l

s.s

Population

T(1)

Si_3.52Al_0.48

1.635

1.633

Si_3.53 Al_0.48

T(2)

Si₄

1.635

1.630

Si₄

M(1)

Mg_1.92Fe_0.08

25.12

2.078

2.073

25.12

Mg_1.92Fe_0.08

M(2)

Mg_1.92Fe_0.08

25.12

2.077

2.071

25.41

Mg_1.76Al_0.14Fe_0.02Cr_0.05 Ti_0.01 Ni_0.01Mn_0.01

M(3)

Mg_0.96Fe_0.04

12.56

2.068

2.070

12.42

Mg_0.97 Fe_0.03

Σ C cat

Mg_4.80 Fe_0.20

Mg_4.65 Al_0.14Fe_0.13Cr_0.05 Ti_0.01 Ni_0.01Mn_0.01

A cat

Na_0.29

3.19

2.94

Na_0.25 K_0.01

B cat

Ca_1.92Fe_0.08

40.48

40.75

Ca_1.80 Fe_0.17 Na_0.03