Table 2.

Fe–O bond distances for the surface I slab model of the (100) surface of goethite

Surface Fe–O distances	BV	PBE96	PBE96 + Grimme2	PBE0	Exp. CTR model
Fe–OH2 (Fe–OII)	Unbound	2.45	2.39	2.41	2.15
Fe–OH (Fe–OI)	2.02	2.10	2.11	2.09	2.09
Fe–O (Fe–Oi, Fe–Oii)	1.91, 1.91	2.01, 1.95	2.01, 1.94	2.01, 1.98	1.95, 1.97

1st layer Fe–O distances	BV	PBE96	PBE96 + Grimme2	PBE0	CTR model
Fe–OH	2.17, 2.17, 2.17	2.14, 2.14, 2.19	2.15, 2.15, 2.16	2.13, 2.13, 2.16	2.19, 2.19, 2.10
Fe–O	1.91, 1.91, 1.91	1.94, 2.01, 2.01	1.93, 2.00, 2.00	1.98, 2.00, 2.00	1.94, 1.93, 1.93

See Fig. 4c for definitions of OI, OII, Oi, and Oii oxygens