Table 1. BEGDB Data Sets Used in the Present Study^a27.

equilibrium data sets
data set	description	number of structures	geometry optimization level	reference energy level
A2455	small complexes of 7–11 atoms	24	CCSD(T)/CBS CP or noCP	CCSD(T)/CBS CP
S2223	small complexes of 8–26 atoms	22	MP2/cc-pVTZ CP noCP or CCSD(T)/cc-pV(T/Q)Z noCP	CCSD(T)/CBS CP
S6646	small complexes of 6–18 atoms	66	MP2/cc-pVTZ CP	CCSD(T)/CBS CP
X4047	complexes with halogenated molecules	40	MP2/cc-pVTZ CP	CCSD(T)/CBS CP
SCAI49	amino acid side-chain complexes of 22–32 atoms	24	DFT TPSS/TZVP noCP	CCSD(T)/CBS CP (D→T)
JSCH23	124 nucleobase complexes and 19 amino acid complexes of 29–41 atoms	143	artificial geometries, NMR structures, crystal structures, X-ray structures, MP2/cc-pVTZ noCP, or MP2/TZVPP noCP	CCSD(T)/CBS noCP or MP2/CBS noCP
L750	large complexes of 48–112 atoms	7	DFT-D TPSS-D/TZVP or other	QCISD(T)/CBS CP or CCSD(T)/CBS CP

nonequilibrium data sets
data set	relative displacements	number of structures	geometry optimization level	reference energy level
S22×545	0.9, 1.0, 1.2, 1.5, 2.0	110	MP2/cc-pVTZ CP or CCSD(T)/cc-pV(T/Q)Z noCP	CCSD(T)/CBS CP
S66×846	0.90, 0.95, 1.00, 1.05, 1.10, 1.25, 1.50, 2.00	528	MP2/cc-pVTZ CP	CCSD(T)/CBS CP
X40×1047	0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.25, 1.50, 2.00	400	MP2/cc-pVTZ CP	CCSD(T)/CBS CP
Ionic48	0.90, 0.95, 1.00, 1.05, 1.10, 1.25, 1.50, 2.00	120	MP2/cc-pVTZ CP	CCSD(T)/CBS CP

^aNote that the names match those on the BEGDB Web site, which are not necessarily consistent with the corresponding publications. For example, the X40, X40×10, and Ionic data sets have also been referred to as “Halogens”, “Halogensx10”, and “Charged HB”.