PM7 Accuracy

Average Unsigned Errors in sets of Molecules (All ref. data)
Statistical Comparison of Accuracy of Methods in MOPAC
Set of Elements	PM7	PM6			No. in set	Set of Elements	PM7		PM6	No. in set
ΔH_f (kcal/mol)						Bond Lengths (Ångstroms)
H C	4.13	4.75			307	H C	0.015		0.016	76
H C N	3.30	3.66			210	H C N	0.016		0.017	92
H C O	3.62	4.26			370	H C O	0.019		0.022	93
H C N O	4.47	4.61			231	H C N O	0.019		0.022	109
H C P	3.98	5.16			9	H C P	0.017		0.017	80
H C O P	8.71	6.74			24	H C O P	0.020		0.023	97
H C S	2.45	3.56			59	H C S	0.015		0.016	81
H C F	4.66	3.91			32	H C F	0.026		0.017	77
H C Cl	2.36	2.46			43	H C Cl	0.015		0.016	77
H C Br	1.80	2.11			16	H C Br	0.016		0.017	77
H C I	1.64	2.16			27	H C I	0.015		0.017	77
All elements (all data)	12.03^NOTE!	8.38			4369	All elements (all data)	0.098^NOTE!		0.087	5035
Dipole Moments (Debye)						Ionization Potential (eV)
All elements (all data)	1.08	0.82			547	All elements (all data)	0.55		0.50	380
Polarizabilities or alpha (Å³)	0.185	0.250			76
PM7 Proteins				PM6 Proteins				Notes on Proteins
PM7-TS Barrier Heights AUE PM7:10.8 Kcal/mol; PM7-TS: 3.8 Kcal/mol; PM6: 12.3 Kcal/mol Notes on Barrier Heights
PM6 faults addressed in PM7
Faults specific to PM7 Caveats regarding PM7
--- Solids ---
Periodic Table - Graph of Densities - Graph of Heats of Formation
Average Unsigned Errors in Solids
ΔH_f (kcal/mol)	PM7	PM6			No.	Geometry (arbitrary units)	PM7		PM6	No
Organic compounds, set 1: H C N O	5.66	15.95			76	Organic compounds, set 1: H C N O	13.66		16.80	209
Organic compounds, set 2: H C N O F P S Cl Br I	6.98	19.77			93	Organic compounds, set 2: H C N O F P S Cl Br I	14.78		18.71	311
Organic compounds, set 3: H Li C N O Na P S K Rb Cs	8.63	20.15			98	Organic compounds, set 3: H Li C N O Na P S K Rb Cs	15.17		19.13	299
All compounds	14.86	557.66			676	All compounds	22.43		34.02	2207
100 worst PM7					100	50 best and 50 worst PM7				100
Miscellaneous (AUE in kcal/mol)						Miscellaneous (AUE in kcal/mol)
Intermolecular Energies: S22 set Notes	0.74		3.38		22	Intermolecular Energies: S66 set Notes	0.78		2.68	66
Intermolecular Energies: L7 set	4.67	13.73			7	Intermolecular Energies: S12L set	21.37		13.37	12
Intermolecular Energies: X40 set	1.70	1.67			40	PM6-D3H4: 1.43 PM6-D3H4X: 1.11
Elements	16.6	248.3			74	Non-Covalent Halogen bond Energies Notes	1.63		2.46	21
Heats of Sublimation Notes	3.9	10.3			36	Heats of Reaction forming Co-Crystals Notes	No thermochemical data			21
Sets of Crystals						Sets of Crystals
Carbohydrates	Mainly mono and di-saccharides					Layer Minerals
Water ions	Zundel, Eigen and related ions					Moh's Scale
Crystal Structure Prediction, blind test						Average Unsigned Error per Element
Alums	[A^I(H₂O)₆][B^III(H₂O)₆](SO₄)₂

Accuracy of PM7 (Notes)