Table 4. Refined structure and cross-fitting of optimized results.

Refined bond-lengths and angles for the tetrahedral (TD) and square-planar (SQ) theory are determined using i-pr and n-pr data, respectively.

	TD theory	SQ theory
Ni—N (Å)	2.017 ± 0.006	2.133 ± 0.004
Ni—O (Å)	2.022 ∓ 0.006	1.960 ∓ 0.003
N—Ni—O (°)	85.12 ± 2.00	88.7 ± 3.0
in fit range	79	57
i-pr
	4.809	10.385
	1.079 ± 0.022	1.15†
α	0.9988 ± 0.0028	1.0122 ± 0.0055
, (Å2)	0.0010†	0.0010†
(Å2)	0.0020†	0.0020†
(Å2)	0.0050 ± 0.0021	0.0081 ± 0.0034
(eV)	−0.42 ± 0.63	4.21 ± 1.08
n-pr
	10.504	8.859
	0.756 ± 0.028	0.921 ± 0.031
α	1.0183 ± 0.0063	1.0080 ± 0.0017
, (Å2)	0.0010†	0.0010†
(Å2)	0.0020†	0.0020†
(Å2)	0.0024 ± 0.0037	0.0090 ± 0.0034
(eV)	3.84 ± 1.16	4.00†

^†Fixed to physical value.