Time stamp: Thu Mar 11 08:54:51 2021

Comparison of Structures of Solid Alums Predicted using PM7 with X-Ray

(All solids - Periodic Table - Home - PM7 and PM6-D3H4 Accuracy - Manual)

HoF Errors: < 2 kcal/mol   < 5 kcal/mol   < 10 kcal/mol   < 20 kcal/mol   < 50 kcal/mol.   Geometries: 0: good, 100: bad

     #     GUI   Heat of formation (Kcal/formula unit) Geometry        Species
                    Ref.        PM7    PM6-D3H4       PM7 PM6-D3H4 
     1  (JSmol)             -1485.4    -1350.3       19.9   31.0   Ammonium aluminum sulfate ((NH4)Al(SO4)2 (12(H2O))
     2  (JSmol)             -1457.2    -1306.3       23.2   33.3   Sodium alum (NaAl(SO4)2 12(H2O))
     3  (JSmol)             -1465.9    -1295.3       26.8   43.7   Potassium alum (KAl(SO4)2 12(H2O))
     4  (JSmol)             -1282.0    -1235.7       38.9   43.7   Ammonium chromium(III) alum ((NH4)Cr(SO4)2 12(H2O))
     5  (JSmol)             -1383.7    -1232.7       34.5   57.9   Chromium potassium alum (KCr(SO4)2 12(H2O))
     6  (JSmol)             -1409.8    -1276.0       20.2   20.2   Rubidium chromium alum (RbCr(III)(SO4)2 12(H2O))
     7  (JSmol)             -1142.9     -935.6       18.7   55.5   Cesium iron(iii) sulfate dodecahydrate (CsFe(SO4)2 (H2O)12) (ICSD 201213)