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III.G.1.a.

Comparison of levels of theory for Li-N


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 1.5657
1
PM3 1.5796
1
PM6 2.0211
3
composite G2 2.0255
3
G3 2.0255
3
G3B3 2.0166
3
CBS-Q 2.0286
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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
hartree fock HF 1.9185
2		 1.9943
3		 1.9943
3		 2.1156
2		 2.0242
3		 2.0242
3		 2.0089
3		 1.9826
3		 1.9826
3		 1.9936
3		 2.0844
2		 2.0280
3		 1.9682
3		 1.9645
3		 2.0025
3		 1.9695
3		 1.9667
3
ROHF   2.0773
2		 2.0773
2		 2.3608
1		 2.1114
2		 2.1114
2		 2.0884
2		 2.0615
2		 2.0615
2		     2.1167
2		 2.0408
2		 2.0346
2		 2.0779
2		 2.0397
2		 2.0363
2
density functional LSDA 1.9437
3		 1.9751
3		 1.9751
3		 2.0330
3		 2.0021
3		 2.0021
3		 1.9960
3		 1.9666
3		 1.9666
3		 1.9759
3		   2.0104
3		 1.9546
3		   1.9799
3		 1.9532
3		  
SVWN   1.8407
1		         1.8526
1		                    
BLYP 1.9701
3		 1.9988
3		 1.9988
3		 2.0604
3		 2.0315
3		 2.0315
3		 2.0365
3		 2.0053
3		 2.0053
3		 2.0081
3		   2.0351
3		 1.9960
3		        
B1B95 1.9897
3		 2.0008
3		 2.0008
3		 1.9016
2		 2.1091
2		 2.1091
2		 1.8644
1		 2.0911
2		 2.0911
2		 1.8440
1		   1.8822
2		 1.9916
3		 1.8334
1		 1.8641
1		 2.2711
1		 1.8380
1
B3LYP 1.9617
3		 1.9830
3		 1.9830
3		 2.0438
3		 2.0146
3		 2.0146
3		 2.0131
3		 1.9834
3		 1.9834
3		 1.9889
3		 2.0972
2		 2.0188
3		 1.9736
3		 1.9673
3		 2.0043
3		 1.9745
3		 1.9703
3
B3LYPultrafine         2.0148
3		                        
B3PW91 1.9823
3		 2.0021
3		 2.0021
3		 2.0662
3		 2.0337
3		 2.0337
3		 2.0294
3		 1.9999
3		 1.9999
3		 2.0075
3		   2.0394
3		 1.9875
3		        
mPW1PW91 1.9795
3		 1.9905
3		 1.9905
3		 2.0530
3		 2.0228
3		 2.0228
3		 2.0184
3		 1.9886
3		 1.9886
3		 1.9969
3		   2.0286
3		 1.9767
3		   2.0846
2		 2.0486
2		  
M06-2X         1.8478
1		                        
PBEPBE 1.9747
3		 2.0024
3		 2.0024
3		 2.0631
3		 2.0335
3		 2.0335
3		 2.0350
3		 2.0030
3		 2.0030
3		 2.0091
3		   2.0384
3		 1.9928
3		 1.8479
1		 2.0243
3		 1.9933
3		 1.8532
1
HSEh1PBE         1.8547
1		                        
Moller Plesset perturbation MP2FC 1.9305
2		 1.9936
3		 1.9936
3		 2.0636
3		 2.0517
3		 2.0391
3		 2.0334
3		 1.9921
3		 1.9921
3		 2.0115
3		 2.1085
2		 2.0467
3		 1.9917
3		 1.9879
3		 2.0349
3		 1.9982
3		 2.0610
2
MP2FU 1.9304
2		 1.9935
3		 1.9935
3		 2.0629
3		 2.0337
3		 2.0337
3		 2.0207
3		 1.9841
3		 1.9841
3		 1.9948
3		   2.0443
3		 1.9720
3		 1.9633
3		 2.0687
2		 2.0213
2		 2.0141
2
ROMP2 2.0107
2		 2.0626
2		 2.0626
2		 2.1508
2		 2.1210
2		 2.1210
2		 2.1079
2		 2.0658
2		 2.0658
2		 2.0885
2		   2.1291
2		 2.0633
2		   2.1066
2		    
MP3         2.0390
3		                        
MP4   1.9975
3		     2.0441
3		       1.9949
3		       2.0691
2		        
B2PLYP         1.8563
1		   1.8641
1		                    
Configuration interaction CID   1.9903
3		 1.9903
3		 2.0628
3		 2.0364
3		     1.9871
3		                  
CISD   1.9977
3		 1.9977
3		 2.0711
3		 2.0394
3		     1.9889
3		                  
Quadratic configuration interaction QCISD   2.0714
2		 2.0714
2		 2.1622
2		 2.1309
2		 2.1309
2		 2.1171
2		 2.0714
2		 2.0714
2		 2.0122
3		   2.1401
2		 1.9907
3		   2.1187
2		 2.0711
2		  
QCISD(T)         2.0451
3		             2.0535
3		 1.9941
3		   1.8858
1		 1.8509
1		  
Coupled Cluster CCD   2.0629
2		 2.0629
2		 2.1498
2		 2.0376
3		 2.0376
3		 2.0304
3		 1.9882
3		 1.9882
3		 2.0093
3		   2.0454
3		 1.9879
3		   2.0348
3		 1.9925
3		  
CCSD         1.8936
2		             1.9323
1		 1.8733
1		        
CCSD(T)         2.0442
3		             2.0526
3		 1.9936
3		 1.9899
3		 2.0426
3		 1.9996
3		 1.9937
3
CCSD(T)=FULL         2.3284
1		             2.1390
2		 2.0451
2		 2.0154
2		 2.0778
2		 2.0241
2		 2.0071
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 2.2322
2		 2.1020
3		 2.0057
3		 1.9763
3		 2.0826
3		 2.0824
3
density functional B3LYP 2.1679
3		 2.1103
3		 2.0479
3		 2.0153
3		 2.0665
3		 2.0682
3
PBEPBE 1.9783
1		 1.9435
1		 1.8675
1		 1.8482
1		 1.9106
1		 1.9152
1
Moller Plesset perturbation MP2FC 2.2427
2		 2.1071
3		 2.0274
3		 2.0002
3		 2.0887
3		 2.0868
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.