. Author manuscript; available in PMC: 2020 Aug 29.

Published in final edited form as: J Phys Chem A. 2019 Aug 15;123(34):7439–7453. doi: 10.1021/acs.jpca.9b05072

Table 7:

Donor-Acceptor Interactions (in kcal/mol) Between Natural Bonding Orbitals in Cu(CH₃)₂.

Spin	Interaction	Geometry^a	DFTB3	B3LYP
α	$n_{C} \to σ_{C u C^{'}}^{*}$	linear	30.8	40.6
α	$n_{C} \to σ_{C u C^{'}}^{*}$	bent	22.2	32.5
β	$n_{C} \to l v_{C u}$	linear	-	107.7
	$n_{C} \to l v_{C u}$	bent	343.6	150.2
	$n_{C} \to σ_{C u C^{'}}^{*}$	linear	32.6	0.1
	$n_{C} \to σ_{C u C^{'}}^{*}$	bent	6.8	0.1

^a.

For structures, see Fig. 7b.