Table 4. Average binding energy per Ca (E_Ca) and the distance between adjacent Ca (d_Ca–Ca) on biphenyl with or without linker groups. Also shown are total number of adsorbed H₂ molecules (n), and their bond lengths (d_HH) and binding energies per H₂ (E_b).

	C12H10	C12H8(B(OH)2)2	C12H6(COOH)4
ECa (eV)	1.16	1.25	1.46
dCa–Ca (Å)	3.658	3.695	4.155
n	12	12	16
Eb (eV)	0.13	0.15	0.16
dHH (Å)	0.765	0.765	0.776