Method

Ground state energy in kJ/mol

Basis set

Basis function increase

Energy change in kJ/mol

MMFF

1.38 × 10³

PM3

1.08 × 10³

VSTO-3G

223 functions

Hartree-Fock

1.56 × 10³

STO-3G

318 functions

95

480

Hartree-Fock

1.57 × 10³

3-21G^*

601 functions

283

10