Table 1.

B3LYP-LOC parameters for transition states

Parameter	Description	Value (kcal/mol)
N/P_sp1.5	Applied for every N or P atom with hybridization that can be considered partly sp and partly sp2	4.47
N/P_sp2.5	Applied for every N or P atom with hybridization that can be considered partly sp2 and partly sp3	4.03
O_sp2.5	Applied for every O with hybridization that can be considered partly sp2 and partly sp3	2.02
MSBC/LSBC_0.5	Applied for every bond of approximate order 0.5 between any atom pairs falling within the description of MSBC and LSBC. Specifically, C---C, C---Cl, N---N, O---O, N---O, F---F, O---Cl, Na---Na, Si---C, S---C, S---O, S---N, any pair of second row atoms other than NaCl	−1.82
AA_1.5	Applied for every bond with approximate bond order 1.5	−0.36
AA_2.5	Applied for every bond with approximate bond order 2.5	−0.91
HH_0.5	Applied for every H-H bond with approximate bond order 0.5	0.55
H_dival	Applied for every transition state in which a hydrogen atom is partly bonded to two atoms, at least one of which is neither carbon nor hydrogen	3.79
ESBC(ii)	Applied for every bond A–B (of order 0.5, 1, or 1.5; where neither A nor B are fluorine or hydrogen, and the bond is not part of a three- or four-membered ring) with neighboring single bond A'-A (where neither A nor A' are fluorine or hydrogen). Likewise, 0.5 ESBC is applied for every neighboring bond A'-A (where neither A nor A' are fluorine or hydrogen) with bond order 0.5 or 1.5 with the same restrictions on A–B stated above.	−0.50(iii) −0.51(iv)
OCT_EXP(ii)	Defined previously for Cl, P, or S atoms that have a valence shell expansion beyond the usual octet. Also applied to any transition state in which an atom (other than hydrogen) experiences an increase in coordination number beyond its octet. This includes the pseudo-penta coordinate transition state of SN2 reactions, for example.	4.92(iii) 3.54(iv)
RH(ii)	Defined previously to apply to every atom on which the localized singly occupied orbital is bonded to a hydrogen atom. Extended here to also apply to any atoms of the transition state with partial radical character. Applied additively for each unpaired electron and each hydrogen.	0.55(iii) 0.34(iv)
RA(ii)	Previously assigned for every atom (of the first or second row) with a localized radical and a single or double bond to another atom. Extended here to include all atoms of the transition state with partial radical character. Applied additively for each unpaired electron and for each bonded first or second row atom.	1.62(iii) 1.71(iv)