. 2020 Aug 5;59(16):11514–11527. doi: 10.1021/acs.inorgchem.0c01320

Table 3. Unbound Electrons and RMSD (with Respect to the X-ray Geometry) in Cluster and QM/MM Models of FeVco.

	system size (atoms)	QM-region size (atoms)	charge (QM region)	unbound electrons	RMSD^c (Å)
vacuum^b	59	59	–6	195	0.166
COSMO^b	59	59	–6	13	0.140
CPCM^a^,^b	59	59	–6	0	0.141
QM/MM	32562	57	–6	29	0.082
QM/MM	32562	83	–3	32	0.085
QM/MM	32562	181	–3	23	0.079
QM/MM	47516	57	–6	62	0.084
QM/MM	531080	57	–6	0	0.085
QM/MM	47516	181	–3	70	0.080
QM/MM	531080	181	–3	0	0.079

Using a Gaussian charge scheme and a scaled van der Waals surface.¹⁰¹

An additional two protons are added to cap residues 423^His and 257^Cys.

The RMSD is defined as the deviation of the [VFe₇S₈C(XO₃)] part with respect to both cofactors in the crystal structure.