Time stamp: Sun Jul 12 17:26:41 2020

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)             -1491.3    -1354.6       20.4   29.4   Ammonium aluminum sulfate ((NH4)Al(SO4)2 (12(H2O))
     2  (JSmol)             -1460.8    -1311.4       24.0   33.3   Sodium alum (NaAl(SO4)2 12(H2O))
     3  (JSmol)             -1472.6    -1301.7       27.0   43.8   Potassium alum (KAl(SO4)2 12(H2O))
     4  (JSmol)             -1263.7    -1242.0       39.2   41.8   Ammonium chromium(III) alum ((NH4)Cr(SO4)2 12(H2O))
     5  (JSmol)             -1389.1    -1230.5       34.5   58.7   Chromium potassium alum (KCr(SO4)2 12(H2O))
     6  (JSmol)             -1414.2    -1273.3       21.8   29.8   Rubidium chromium alum (RbCr(III)(SO4)2 12(H2O))
     7  (JSmol)             -1131.5     -935.5       18.8   57.0   Cesium iron(iii) sulfate dodecahydrate (CsFe(SO4)2 (H2O)12) (ICSD 201213)