TABLE 1.

Calculated Geometrical Parameters of the Transition States for the First Step of the Intramolecular Decomposition Route (Figure 2)

Geometrical parameter, Å	PDDG	PDDG GB/SA	B3LYP/6-311++G**	MP2/6-311++G** ICPMa	QM/MM MC/FEP
	TS3				TSw1	TSw2	TSw3	TSw4
R(N1-H1)	1.48	1.16	1.15	1.01	1.26	1.02	1.58	1.28
R(O-H1)	1.12	1.44	1.40	1.94	1.34	1.58	1.02	1.32
R(N2-H2)	1.50	1.04	1.27	1.99	0.98	1.30	1.38	1.62
R(O-H2)	1.10	1.56	1.23	0.96	1.62	1.30	1.22	0.98
R(C-N1)	1.51	1.50	1.57		1.50	1.51	1.47	1.51
R(C-N2)	1.36	1.40	1.31		1.48	1.42	1.42	1.41

^aResults from Ref. 17.