Table 1. Functionals Assessed in the Benchmark Calculations^a.

Functional	Exchange	Correlation	Class	Number of parameters	References
SCS-RS-PBE-P86	PBE	P86	RS DH	4	(90)
SOS-RS-PBE-P86	PBE	P86	RS DH	3	(90)
SCS-ωPBEPP86	PBE	P86	LC DH	7	(77)
SOS-ωPBEPP86	PBE	P86	LC DH	5	(77)
DSD-PBEP86	PBE	P86	global DH	4	(113)
PBE0-2	PBE	PBE	global DH	2	(114)
SOS-PBE0-2	PBE	PBE	global DH	3	(115)
PBE-QIDH	PBE	PBE	global DH	2	(116)
B2GPPLYP	B88	LYP	global DH	2	(117)
ωB97X-D	B97	B97	LC hybrid	18	(118)
CAM-B3LYP	B88	LYP	LC hybrid	3	(119)
PBE0	PBE	PBE	global hybrid	1	(120)

^aBoth the CIS(D)- and ADC(2)-based approaches are discussed for all the DH functionals, except for SOS/SCS-ωPBEPP86. For more details regarding the ADC(2)-based formalism, see refs (82) and (91).