Description of Weak Halogen Bonding Using Various Levels of Symmetry-Adapted Perturbation Theory Combined with Effective Core Potentials

Table 2

Errors (RMSE, rRMSE (%), and MSE; in kcal/mol or %) in obtained from various SAPT methods. The errors without parentheses have been calculated relative to the CCSD(T)/def2-QZVPP+mb results, while those put in parentheses are based on the CCSD(T)/CBS reference values of .

Method	RMSE	rRMSE (%)	MSE
SAPT0	0.28; (0.23)	21; (16)	−0.26; (−0.21)
SAPT0 +	0.67; (0.62)	51; (44)	−0.64; (−0.59)
SAPT2	0.39; (0.34)	36; (29)	−0.38; (−0.33)
SAPT2 +	0.78; (0.73)	66; (58)	−0.76; (−0.71)
SAPT2+	0.30; (0.25)	27; (21)	−0.30; (−0.25)
SAPT2+ +	0.70; (0.65)	58; (50)	−0.67; (−0.62)
SAPT2+	0.06; (0.04)	7; (3)	−0.05; (−0.01)
SAPT2+ +	0.44; (0.39)	37; (30)	−0.43; (−0.38)
SAPT2+3	0.13; (0.16)	9; (9)	0.03; (0.08)
SAPT2+3 +	0.51; (0.46)	41; (34)	−0.49; (−0.44)
SAPT(DFT)	0.12; (0.16)	7; (10)	0.08; (0.14)
SAPT(DFT) +	0.30; (0.25)	26; (20)	−0.29; (−0.24)