Table 2. Errors Using RMSE When Compared with FCI for the Gradient of Ground-State Trigonal Planar NH₃ and Mean Number of Determinants across the 19 Bond Lengths Considered When Employing 6-31G and One Frozen Orbital.

Method	Gradient Error (hartree/bohr)	Mean Determinants
HF	1.57 × 10–2	1
MCCI 1 × 10–3	0.0990 × 10–2	1649
MCCI 5 × 10–4	0.0585 × 10–2	3550
MCCI 2 × 10–4	0.0248 × 10–2	8381