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III.G.1.a.

Comparison of levels of theory for Li-O


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 2.1855
4
PM3 1.7717
7
PM6 1.9387
8
composite G2 1.8181
9
G3 1.8268
7
G3B3 1.8334
7
G4 1.7990
8
CBS-Q 1.8359
7

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
hartree fock HF 1.6710
10
1.7353
11
1.7353
11
1.7916
11
1.7546
16
1.7772
11
1.7705
11
1.7609
11
1.7696
11
1.7615
11
1.5884
3
1.7712
9
1.7964
11
1.7927
9
1.7554
11
1.8052
9
1.7599
11
1.7717
10
ROHF 1.6930
3
1.7504
8
1.7504
8
1.8152
7
1.7884
8
1.7884
8
1.7786
8
1.7728
8
1.7863
7
1.8039
3
  1.7900
2
1.8117
7
1.7782
7
1.7707
7
1.7912
7
1.7747
7
1.7704
7
density functional LSDA 1.6538
11
1.7429
9
1.7429
9
1.7899
9
1.7736
11
1.7736
11
1.7757
11
1.7614
11
1.7616
11
1.7623
11
  1.7880
2
1.7878
11
1.7572
11
1.7912
3
1.7676
11
1.8064
8
1.7901
3
SVWN   1.7531
6
    1.7356
7
1.7692
2
1.7817
8
1.7604
2
1.7604
2
1.7588
2
    1.7825
2
1.7564
2
  1.7649
2
1.7527
2
 
BLYP 1.6952
10
1.7657
11
1.7658
11
1.8102
11
1.7985
11
1.7986
11
1.8010
11
1.7819
11
1.7912
11
1.7897
11
  1.8142
2
1.8459
9
1.8215
9
  1.6648
2
   
B1B95 1.6958
11
1.7580
11
1.7219
10
1.8242
6
1.7790
6
1.7574
7
1.6959
2
1.7400
8
1.7401
8
1.7828
11
  1.8023
2
1.8101
7
1.8159
7
1.8174
3
1.7816
6
1.6118
1
1.6076
1
B3LYP 1.6915
11
1.7399
11
1.7399
11
1.7873
11
1.7764
11
1.7764
11
1.7829
11
1.7661
11
1.8079
9
1.7663
11
1.6367
2
1.7947
9
1.7972
11
1.8030
9
1.7813
10
1.8156
9
1.7706
11
1.7815
10
B3LYPultrafine         1.8012
10
                      1.7758
9
 
B3PW91 1.7312
9
1.7496
11
1.7496
11
1.7996
11
1.7875
11
1.7875
11
1.7907
11
1.7763
11
1.8192
9
1.7756
11
  1.8055
2
1.8439
9
1.8123
9
  1.6545
2
   
mPW1PW91 1.7161
10
1.7436
11
1.7870
9
1.8035
11
1.7821
11
1.7820
11
1.7844
11
1.7701
11
1.7792
11
1.7780
11
  1.7995
2
1.8371
9
1.8052
9
  1.7406
6
1.7690
4
 
M06-2X 1.6808
2
1.7392
2
1.7392
2
1.7790
2
1.7849
8
1.7796
2
1.7757
2
1.7703
2
1.7703
2
1.7672
2
  1.7938
2
1.7888
2
1.7668
2
  1.7775
2
1.7632
2
 
PBEPBE 1.7207
9
1.7670
11
1.7996
9
1.8470
9
1.8007
11
1.8007
11
1.8084
11
1.7910
11
1.7912
11
1.7905
11
1.6473
2
1.8117
2
1.8134
11
1.7878
11
1.8934
4
1.8603
5
1.8078
6
1.8928
4
PBEPBEultrafine         1.6527
2
                         
PBE1PBE 1.6880
2
1.7431
2
1.7431
2
1.7836
2
1.7729
9
1.7841
2
1.7823
2
1.7748
2
1.7748
2
1.7721
2
  1.7974
2
1.7945
2
1.7703
2
  1.7834
2
1.7670
2
 
HSEh1PBE 1.6882
2
1.7435
2
1.7435
2
1.7834
2
1.7922
8
1.7840
2
1.7826
2
1.7751
2
1.7751
2
1.7725
2
  1.7985
2
1.7946
2
1.7710
2
  1.7836
2
1.7677
2
 
TPSSh         1.7011
9
  1.7011
9
            1.6923
9
       
Moller Plesset perturbation MP2 1.7376
8
1.7685
11
1.7685
11
1.8264
11
1.7823
13
1.8077
11
1.8113
11
1.7873
11
1.7969
11
1.7941
11
1.6135
1
1.8325
9
1.8293
11
1.8310
9
1.8301
9
1.8195
11
1.8163
10
1.7705
6
MP2=FULL 1.7377
8
1.7682
11
1.8165
9
1.8740
9
1.7779
13
1.8032
11
1.7853
11
1.7816
11
1.8264
9
1.8260
9
  1.8122
2
1.8643
9
1.7817
11
1.8121
9
1.7581
8
1.8269
8
1.7609
5
ROMP2 1.7279
6
1.8046
7
1.8046
7
1.8577
7
1.8385
7
1.8385
7
1.8371
7
1.8203
7
1.8203
7
1.8221
7
  1.8131
2
1.8518
7
1.8179
7
1.8449
3
1.8388
7
1.8576
3
1.8488
3
MP3         1.8157
10
  1.6999
9
                     
MP3=FULL         1.6973
9
  1.6859
9
                     
MP4 1.6257
1
1.8317
8
    1.8202
10
    1.5855
2
1.8778
7
        1.7789
8
       
B2PLYP         1.8064
6
                1.6828
7
       
Configuration interaction CID 1.5385
1
1.7928
9
1.7928
9
1.8560
9
1.7932
11
    1.7701
11
                   
CISD 1.5447
1
1.7964
9
1.7964
9
1.8603
9
1.7955
11
    1.8153
9
                   
Quadratic configuration interaction QCISD 1.5564
1
1.7702
10
1.8240
8
1.8920
8
1.8175
10
1.8695
8
1.8200
10
1.7940
10
1.8046
10
1.8507
8
  1.8118
2
1.8387
10
1.8051
10
  1.8091
4
1.7880
4
 
QCISD(T)         1.8184
10
    1.5993
3
      1.8142
2
1.8843
8
1.8490
8
  1.9353
5
1.9157
5
 
Coupled Cluster CCD 1.5424
1
1.7955
9
1.7955
9
1.8592
9
1.7962
11
1.8385
9
1.8379
9
1.7732
11
1.8162
9
1.8214
9
  1.8095
2
1.8158
11
1.8154
9
  1.8613
8
1.8406
8
 
CCSD         1.7969
9
    1.5819
2
        1.8141
2
1.7880
2
       
CCSD(T)         1.7308
9
1.6086
2
  1.5991
3
    1.7101
1
1.8138
2
1.8297
11
1.7954
11
1.8450
8
1.8500
9
1.8108
10
1.8579
4
CCSD(T)=FULL         1.7865
7
            1.8125
2
1.8142
4
1.7715
5
1.8437
6
1.7546
4
1.7643
4
1.8295
4

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 1.8955
11
1.8451
11
1.7586
11
1.7443
11
1.8154
11
1.8068
11
density functional B1B95 1.7331
2
1.7156
2
       
B3LYP 1.8951
11
1.8608
11
1.7862
11
1.7757
11
1.8207
11
1.8193
11
Moller Plesset perturbation MP2 1.9305
11
1.8817
11
1.8000
11
1.7818
11
1.8544
11
1.8471
11
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.