Table 3. Mayer bond orders and atomic charges of NPrO and NPrO^– calculated at the B3LYP/TZ2P level of theory.

	Distance (Å)		Bond order	Charge
				Atom	Mulliken	Natural
NPrO	Pr–O	1.765	2.1	Pr	1.49	1.49
	Pr–N	1.677	3.1	O	–0.70	–0.76
	N–O	3.442	0.1	N	–0.78	–0.73
NPrO–	Pr–O	1.933	1.9	Pr	1.29	1.14
	Pr–N	1.790	3.0	O	–1.08	–1.10
	N–O	3.722	0.1	N	–1.20	–1.05