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III.G.1.a.

Comparison of levels of theory for O-Al


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 1.5554
2
PM3 1.6062
3
PM6 1.5417
3
composite G2 1.6456
3
G3 1.6456
3
G3B3 1.6347
3
CBS-Q 1.6530
3
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 1.6399
3		 1.6999
3		 1.6508
3		 1.7543
3		 1.6456
3		 1.6456
3		 1.6531
3		 1.6455
3		 1.6453
3		 1.6303
3		 1.6858
1		 1.6490
3		 1.6824
3		 1.6393
3		 1.6319
3		 1.6700
3		 1.6395
3		 1.6320
3		 1.6819
1
ROHF   1.7195
1		 1.6917
1		   1.7044
1		 1.7044
1		 1.7165
1		 1.7048
1		         1.7375
1		 1.7006
1		          
density functional LSDA 1.6016
3		 1.6416
3		 1.6317
3		 1.6813
3		 1.6267
3		 1.6267
3		 1.6333
3		 1.6279
3		 1.6279
3		 1.6134
3		     1.6479
3		 1.6207
3		 1.6145
2		 1.6433
3		 1.6213
2		 1.6147
2		  
SVWN   1.6616
3		     1.6372
2		   1.6333
3		                        
BLYP 1.6220
3		 1.6822
3		 1.6527
3		 1.7050
3		 1.6504
3		 1.6504
3		 1.6587
3		 1.6535
3		 1.6535
3		 1.6372
3		     1.6708
3		 1.6463
3		   1.6694
1		      
B1B95 1.6022
3		 1.6439
3		 1.6342
3		 1.6881
3		 1.6299
3		 1.6303
3		 1.6372
3		 1.6314
3		 1.6314
3		 1.6182
3		     1.6538
3		 1.6257
3		 1.6180
2		 1.6471
2		 1.6248
2		 1.6183
2		  
B3LYP 1.6082
3		 1.6680
3		 1.6386
3		 1.6925
3		 1.6346
3		 1.6346
3		 1.6426
3		 1.6368
3		 1.6351
2		 1.6221
3		 1.6275
1		 1.6388
3		 1.6572
3		 1.6309
3		 1.6250
3		 1.6529
3		 1.6318
3		 1.6253
3		 1.6240
1
B3LYPultrafine         1.6346
3		                            
B3PW91 1.6058
2		 1.6666
3		 1.6369
3		 1.6894
3		 1.6311
3		 1.6311
3		 1.6378
3		 1.6323
3		 1.6312
2		 1.6189
3		     1.6545
3		 1.6267
3		   1.6507
1		      
mPW1PW91 1.6024
2		 1.6638
3		 1.6320
2		 1.6875
3		 1.6280
3		 1.6280
3		 1.6347
3		 1.6291
3		 1.6291
3		 1.6158
3		     1.6520
3		 1.6236
3		   1.6486
1		      
M06-2X         1.6219
3		                            
PBEPBE 1.6190
2		 1.6806
3		 1.6500
2		 1.7015
2		 1.6462
3		 1.6462
3		 1.6533
3		 1.6479
3		 1.6479
3		 1.6333
3		 1.6351
1		   1.6680
3		 1.6412
3		 1.6348
2		   1.6423
1		 1.6353
2		 1.6314
1
PBEPBEultrafine         1.6465
1		                            
HSEh1PBE         1.6295
3		                            
Moller Plesset perturbation MP2FC 1.5635
2		 1.6696
3		 1.6427
3		 1.6913
3		 1.6325
3		 1.6325
3		 1.6293
3		 1.6293
3		 1.6294
3		 1.6194
3		   1.6330
3		 1.6547
3		 1.6238
3		 1.6173
3		 1.6497
3		 1.6271
3		 1.6172
1		 1.6076
1
MP2FU 1.5647
2		 1.6705
3		 1.6303
2		 1.6660
2		 1.6332
3		 1.6332
3		 1.6299
3		 1.6294
3		 1.6220
2		 1.6137
2		     1.6553
3		 1.6175
2		 1.5990
3		 1.6554
1		     1.5901
1
MP3         1.6429
3		                            
MP4   1.9208
2		     1.6547
3		       1.6478
2		         1.6353
3		          
B2PLYP         1.6279
3		   1.6360
3		                        
Configuration interaction CID   1.6534
2		 1.6299
2		 1.6775
2		 1.6397
3		     1.6355
3		                      
CISD   1.6723
2		 1.6416
2		 1.6980
2		 1.6420
3		     1.6283
2		                      
Quadratic configuration interaction QCISD   1.7047
3		 1.6678
2		 1.7354
2		 1.6559
3		 1.6572
2		 1.6622
3		 1.6503
3		 1.6503
3		 1.6380
2		     1.6822
3		 1.6427
3		         1.6328
1
QCISD(T)         1.6566
2		               1.6830
2		 1.6435
2		   1.6778
2		 1.6466
2		    
Coupled Cluster CCD   1.6538
2		 1.6326
2		 1.6763
2		 1.6430
3		 1.6293
2		 1.6384
2		 1.6389
3		 1.6255
2		 1.6176
2		     1.6483
2		 1.6221
2		   1.6500
2		 1.6252
2		    
CCSD         1.6471
3		                            
CCSD(T)   1.6777
1		     1.6542
1		 1.6541
1		 1.6595
1		   1.6475
1		       1.6768
2		 1.6395
3		 1.6135
1		 1.6735
2		 1.6420
2		   1.6305
1
CCSD(T)=FULL         1.6516
2		                   1.6181
2		        
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 1.7596
3		 1.6462
3		 1.7625
3		 1.6527
3		 1.7383
3		 1.7378
3
density functional B1B95 1.6909
1		 1.6357
1		        
B3LYP 1.6914
3		 1.6360
3		 1.6946
3		 1.6411
3		 1.6796
3		 1.6791
3
Moller Plesset perturbation MP2FC 1.6916
3		 1.6259
3		 1.6622
2		 1.6275
3		 1.6855
3		 1.6819
3
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.