Table 1.

Effect of pressure on ZIF-8 for different gases

Pressure CH4 (GPa)	Unit cell volume (Å3)	% change in uc volume	SAV (Å3)	θ (°)	4MR diameter (Å)	6MR diameter (Å)
0.00	4924.5 (2)	0.00	2497	65.1	0.8 (1)	3.0 (1)
0.30	4993.1 (1)	1.39	2580	58.7	0.7 (1)	3.1 (1)
0.50	4974.9 (4)	1.02	2551	58.9	0.7 (1)	3.1 (1)
0.70a	5063.8 (4)	2.83	2657	86.6	2.5 (1)	3.3 (1)
1.10a	4998.5 (4)	1.50	2710	87.4	2.5 (1)	3.2 (1)
1.40a	4995.1 (3)	1.43	2586	87.8	2.5 (1)	3.2 (1)

Pressure O2 (GPa)	Unit cell volume (Å3)	% change in uc volume	SAV (Å3)	θ (°)	4MR diameter (Å)	6MR diameter (Å)
0.00	4924.5 (2)	0.00	2514	65.1	0.8 (1)	3.0 (1)
0.21	4919.8 (5)	−0.10	2487	64.9	0.9 (1)	2.9 (1)
0.50	4898.2 (3)	−0.53	2457	66.7	0.8 (1)	2.9 (1)
0.75a	4908.0 (4)	−0.33	2522	87.2	2.2 (1)	3.6 (1)
1.20a	4782.0 (9)	−2.89	2356	86.9	2.2 (1)	3.4 (1)
2.00a	4579.9 (6)	−7.00	2255	86.6	2.4 (1)	3.1 (1)

Pressure N2 (GPa)	Unit cell volume (Å3)	% change in uc volume	SAV (Å3)	θ (°)	4MR diameter (Å)	6MR diameter (Å)
0.00	4924.55 (23)	0.00	2497	65.1	0.8 (1)	3.0 (1)
0.21a	4972.3 (4)	0.97	2548	86.2	2.5 (1)	3.4 (1)
0.74a	4976 (1)	1.04	2525	88.0	2.3 (1)	3.5 (1)
1.03a	4972.8 (9)	0.98	2512	87.7	2.3 (1)	3.5 (1)
1.33a	4940.8 (3)	0.33	2402	82.8	2.0 (1)	3.5 (1)
1.85a	4784.5 (6)	−2.84	2364	86.2	2.0 (1)	3.5 (1)
2.72a	4579.3 (5)	−7.01	2223	89.3	2.2 (1)	3.2 (1)
3.25a	4454.0 (3)	−9.55	2054	89.2	2.2 (1)	3.0 (1)

Pressure Ar (GPa)	Unit cell volume (Å3)	% change in uc volume	SAV (Å3)	θ (°)	4MR diameter (Å)	6MR diameter (Å)
0.00	4924.5 (2)	0.00	2497	65.1	0.8 (1)	3.0 (1)
0.75a	4820.6 (3)	−2.11	2458	86.7	2.5 (1)	3.3 (1)
1.20a	4727 (5)	−3.99	2405	87.3	2.4 (1)	3.3 (1)
1.50a	4567.9 (4)	−7.24	2256	87.7	2.4 (1)	3.2 (1)

Diameters of 4MR and 6MR calculated using the void analysis routine in Mercury, (grid spacing of 0.2 Å)¹⁴ SAV solvent accessible volume, calculated using PLATON³⁷

^a The ZIF-8-HP phase