Table 1. Results from multi-component EXAFS fits of the He-activated state at 400 °C for the whole multi-composition sample series. Fits are performed in the k-range (2.4–11.0) Å^–1 and R-range (1.0–3.2) Å, resulting in a number of independent parameters πΔRΔk/2 > 12.³⁴ For all of the fits, geometries of 1Al Z[Cu(ii)OH], 1Al ZCu(i), and 2Al Z₂Cu(ii) Cu-species (i.e. radial shift parameters ΔR _i ) have been fixed based on the results of mono-component fits on the ‘purest’ He-activated states (1Al Z[Cu(ii)OH] model for sample (0.6; 19), 1Al ZCu(i) in the 6r for sample (0.5; 15), 2Al Z₂Cu(ii) in the 6r with Al–Si–Si–Al linkage for sample (0.1; 5); see the ESI Section 5.3), and S ₀ ² has been set to unity.

Composition (Cu/Al; Si/Al)	(0.1; 5)	(0.3; 5)	(0.1; 14)	(0.5; 15)	(0.6; 19)	(0.6; 29)
Fit R-factor	0.007	0.007	0.044	0.017	0.006	0.014
N par (N ind)	8 (12)	8 (12)	8 (12)	8 (12)	8 (12)	8 (12)
ΔE (eV)	–5.8 ± 0.6	–6.0 ± 0.5	–7 ± 1	–7.0 ± 0.8	–3.2 ± 0.4	–3.8 ± 0.4
A Z[Cu(ii)OH]	0.0 ± 0.2	0.0 ± 0.1	0.0 ± 0.3	0.1 ± 0.2	1.0 ± 0.2	0.4 ± 0.1
A ZCu(i)	0.2 ± 0.1	0.4 ± 0.1	0.7 ± 0.1	0.8 ± 0.2	0.0 ± 0.1	0.6 ± 0.2
A Z2Cu(ii)	0.8 ± 0.2	0.6 ± 0.1	0.3 ± 0.1	0.1 ± 0.1	0.0 ± 0.1	0.0 ± 0.1
σ O(ef) 2 (Å2)	0.007 ± 0.002	0.008 ± 0.002	0.008 ± 0.002	0.007 ± 0.002	0.007 ± 0.001	0.007 ± 0.001
σ O(fw) 2 (Å2)	0.007 ± 0.001	0.007 ± 0.001	0.008 ± 0.001	0.009 ± 0.001	0.004 ± 0.001	0.007 ± 0.001
σ T(fw) 2 (Å2)	0.011 ± 0.002	0.014 ± 0.003	0.010 ± 0.002	0.012 ± 0.002	0.014 ± 0.003	0.009 ± 0.001