Table 5. Samples with the Six Highest Log PI Values.

metal oxides	log PI [-]	PICO2 [-]	PIH2 [-]	ratio of metal 1 [-]	ratio of metal 2 [-]	ratio of metal 3 [-]	precipitation method	hydrogen excess
K·Cu·Ga	–2.86	0.22	0.26	0.18	0.46	0.36	coprecipitation	less
Mg·Cu·Ga	–3.22	0.22	0.18	0.17	0.41	0.42	coprecipitation	less
Ca·Cu·Ga	–4.02	0.18	0.10	0.17	0.38	0.45	coprecipitation	less
Cu·Ga·Sr	–4.48	0.17	0.07	0.42	0.42	0.16	coprecipitation	less
Mn·Cu·Ga	–6.69	0.11	0.01	0.08	0.39	0.53	coprecipitation	less