Accuracy of PM7 (Notes)

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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

ΔHf  (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)

12.03NOTE! 8.38 4369

All elements (all data)

0.098NOTE! 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

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

--- Solids ---

Periodic Table - Graph of Densities - Graph of Heats of Formation

Average Unsigned Errors in Solids

ΔHf  (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 [AI(H2O)6][BIII(H2O)6](SO4)2

Faults in PM7

Caveats regarding PM7

1: This set includes reference data of possible low accuracy