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

Table 3

Errors (RMSE, rRMSE  (%), and MSE; in kcal/mol or %) in obtained from various wave function theory methods within the supermolecular approach. 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
HF	2.19; (2.24)	200; (193)	2.16; (2.22)
MP2	0.46; (0.40)	41; (34)	−0.45; (−0.39)
SCS-MP2	0.11; (0.16)	10; (14)	0.10; (0.15)
SCS(MI)-MP2	0.08; (0.05)	7; (3)	−0.06; (−0.01)
MP2C	0.06; (0.08)	3; (5)	0.01; (0.06)
MP2.5	0.06; (0.11)	4; (8)	0.04; (0.10)
MP3	0.55; (0.60)	48; (50)	0.54; (0.59)
MP4(SDQ)	0.23; (0.28)	23; (26)	0.22; (0.27)
MP4	0.34; (0.29)	31; (25)	−0.33; (−0.28)
CCSD	0.40; (0.45)	36; (38)	0.39; (0.44)