return to home page

III.G.1.a.

Comparison of levels of theory for N-Li


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 PM6 2.0211
3
composite G2 2.0255
3
G3 2.0255
3
G3B3 2.0166
3
G4 2.0108
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
2.0595
5
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
                    2.0066
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
PBE1PBE         2.0831
2
                       
HSEh1PBE         1.8547
1
                       
TPSSh         1.9864
3
  1.9822
3
          1.9659
3
       
Moller Plesset perturbation MP2 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
MP2=FULL 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
  1.9947
3
                   
MP3=FULL         1.9917
3
  1.9793
3
                   
MP4   1.9975
3
    2.0441
3
      1.9949
3
      2.0691
2
       
B2PLYP         1.8563
1
              1.9642
3
       
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 MP2 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.