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III.G.1.a.

Comparison of levels of theory for Al-Cl


Click on an entry for a histogram of the values.
The subscript refers to how many bonds of that type have been calculated.
average calculated bond lengths (Å)
Methods with predefined basis sets
semi-empirical AM1 2.0340
2
PM3 2.0305
7
PM6 2.0743
9
composite G2 2.1103
9
G3 2.1103
9
G3B3 2.1204
9
CBS-Q 2.1093
9
average calculated bond lengths (Å)
Methods with standard basis sets
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z
hartree fock HF 2.1123
9		 2.2070
9		 2.1065
9		 2.2140
9		 2.1102
9		 2.1103
9		 2.1071
9		 2.1043
9		 2.1043
9		 2.1028
9		 2.0650
6		 2.1142
9		 2.1332
9		 2.1080
9		 2.1492
1		 2.1338
9		 2.1033
9		 2.1494
1		 2.0960
8
ROHF         2.1880
2		                            
density functional LSDA 2.1014
9		 2.1443
9		 2.0919
9		 2.1888
9		 2.0980
9		 2.0980
9		 2.0958
9		 2.0922
9		 2.0922
9		 2.0686
7		     2.1199
9		 2.0940
9		   2.1182
9		 2.1420
3		    
SVWN   2.1722
8		     2.0917
8		   2.0888
8		                        
BLYP 2.1392
9		 2.2204
9		 2.1298
9		 2.2342
9		 2.1392
9		 2.1392
9		 2.1378
9		 2.1365
9		 2.1365
9		 2.1285
9		     2.1600
9		 2.1365
9		   2.1225
6		      
B1B95 2.1141
9		 2.1542
9		 2.1018
9		 2.2005
9		 2.1052
9		 2.1064
9		 2.1130
8		 2.1013
9		 2.1013
9		 2.0988
9		     2.1288
9		 2.1039
9		   2.1344
8		 2.2166
2		    
B3LYP 2.1246
9		 2.2057
9		 2.1131
9		 2.2167
9		 2.1210
9		 2.1209
9		 2.1191
9		 2.1170
9		 2.1922
3		 2.1109
9		 2.0735
6		 2.1242
9		 2.1421
9		 2.1182
9		 2.1620
1		 2.1410
9		 2.1129
9		 2.1623
1		 2.1043
8
B3LYPultrafine         2.1210
9		   2.0806
3		                        
B3PW91 2.2209
3		 2.2006
9		 2.1080
9		 2.2080
9		 2.1123
9		 2.1123
9		 2.1098
9		 2.1066
9		 2.1757
3		 2.1039
9		     2.1347
9		 2.1097
9		   2.1002
6		      
mPW1PW91 2.2166
3		 2.1967
9		 2.1668
3		 2.2036
9		 2.1079
9		 2.1079
9		 2.1054
9		 2.1022
9		 2.1022
9		 2.0996
9		     2.1304
9		 2.1054
9		   2.1104
7		 2.1557
1		    
M06-2X 2.1609
1		 2.2582
1		 2.1479
1		 2.2773
1		 2.1051
9		 2.1593
1		 2.1608
1		 2.1572
1		 2.1572
1		 2.1479
1		     2.1851
1		 2.1560
1		   2.1941
1		 2.1568
1		    
PBEPBE 2.2259
3		 2.2093
9		 2.1834
3		 2.3090
3		 2.1249
9		 2.1249
9		 2.1231
9		 2.1205
9		 2.1204
9		 2.1153
9		 2.0785
6		   2.1467
9		 2.1223
9		   2.2104
1		 2.1006
7		    
PBEPBEultrafine         2.0917
6		                            
HSEh1PBE 2.1600
1		 2.2655
1		 2.1516
1		 2.2776
1		 2.1091
9		 2.1600
1		 2.1620
1		 2.1581
1		 2.1581
1		 2.1478
1		     2.1872
1		 2.1565
1		   2.1952
1		 2.1572
1		    
Moller Plesset perturbation MP2FC 2.2329
3		 2.2202
9		 2.0939
9		 2.2316
9		 2.0978
9		 2.0978
9		 2.0952
9		 2.0928
9		 2.0928
9		 2.1007
9		   2.1062
9		 2.1314
9		 2.1078
9		 2.1440
1		 2.1431
9		 2.1594
3		 2.1459
1		 2.0961
8
MP2FU 2.2324
3		 2.2203
9		 2.1454
3		 2.3286
3		 2.0947
9		 2.0947
9		 2.0921
9		 2.0911
9		 2.1504
3		 2.1458
3		     2.1290
9		 2.1593
3		 2.1102
1		 2.1198
7		 2.1458
1		 2.1012
1		 2.0848
8
MP3         2.0977
9		                            
MP4   2.3213
3		     2.1022
9		       2.1562
3		         2.0953
2		          
B2PLYP 2.1637
1		 2.2758
1		 2.1466
1		 2.2916
1		 2.1098
9		 2.1568
1		 2.1077
9		 2.1568
1		 2.1568
1		 2.1510
1		     2.1882
1		 2.1600
1		   2.2046
1		 2.1636
1		    
Configuration interaction CID   2.3210
3		 2.1519
3		 2.3442
3		 2.0988
9		     2.1546
3		                      
CISD   2.3237
3		 2.1536
3		 2.3471
3		 2.0996
9		     2.1561
3		                      
Quadratic configuration interaction QCISD   2.2290
9		 2.1538
3		 2.3520
3		 2.1020
9		 2.1602
3		 2.1550
3		 2.0957
9		 2.0957
9		 2.1617
3		     2.2053
3		 2.1709
3		   2.2088
1		 2.1590
1		    
QCISD(T)         2.1607
3		               2.2062
3		 2.1716
3		   2.2261
2		 2.1693
2		    
Coupled Cluster CCD   2.3232
3		 2.1508
3		 2.3470
3		 2.0997
9		 2.1573
3		 2.1517
3		 2.1540
3		 2.1540
3		 2.1600
3		     2.2021
3		 2.1695
3		   2.2156
3		 2.1619
3		    
CCSD         2.1012
9		               2.1815
1		 2.1529
1		          
CCSD(T)         2.1028
9		               2.2054
3		 2.1712
3		 2.1447
1		 2.2202
3		 2.1657
3		 2.1471
1		  
CCSD(T)=FULL         2.1576
3		               2.1803
1		 2.1477
1		   2.2067
1		 2.1488
1		    
average calculated bond lengths (Å)
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 2.2111
9		 2.1149
9		 2.2145
9		 2.1149
9		 2.2042
9		 2.1936
9
density functional B1B95 2.1683
6		 2.0926
6		        
B3LYP 2.2247
9		 2.1305
9		 2.2250
9		 2.1305
9		 2.2165
9		 2.2022
9
Moller Plesset perturbation MP2FC 2.2324
9		 2.1129
9		 2.2339
9		 2.1096
9		 2.2175
9		 2.2069
9
For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.