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III.G.1.a.

Comparison of levels of theory for Br-H


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 1.5020
1
PM3 1.5533
1
PM6 1.7089
3
composite G2 2.0289
3
G3B3 2.0033
3
G4 1.9929
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
hartree fock HF 1.9157
2
2.0304
3
1.9753
3
2.0038
3
2.0308
6
1.9666
3
2.4408
3
2.2992
3
2.5956
2
1.9952
3
1.4074
1
2.2165
3
2.0161
3
2.1132
3
2.1341
3
2.1381
3
2.1540
3
2.1518
3
density functional LSDA 1.7343
3
1.7307
3
1.7223
3
1.7350
3
1.7319
3
1.7054
3
1.6673
3
1.7033
3
1.6872
3
1.7004
3
    1.7053
3
1.6838
3
1.7942
2
1.5744
3
1.5461
2
1.5329
2
SVWN   1.7575
3
    1.7319
3
  1.6672
3
                     
BLYP 1.9230
2
1.9780
2
1.7844
3
1.7884
3
1.7922
3
1.7744
3
1.7650
3
1.7671
3
1.9126
2
1.7618
3
    1.7748
3
1.7540
3
  1.4441
1
   
B1B95 1.7386
3
1.7552
3
1.7484
3
1.7560
3
1.7586
3
1.7414
3
1.7546
3
1.7443
3
1.7322
3
1.7333
3
    1.7412
3
1.7315
3
1.8801
2
1.7092
3
1.8255
2
1.8209
2
B3LYP 1.7411
3
1.7870
3
1.7552
3
1.7629
3
1.7654
3
1.7474
3
1.7525
3
1.7488
3
1.8908
2
1.7376
3
  1.7358
3
1.7481
3
1.7352
3
1.7290
3
1.7076
3
1.6927
3
1.6896
3
B3LYPultrafine         1.9268
2
                      1.9892
3
 
B3PW91 1.8911
2
1.7729
3
1.7400
3
1.7505
3
1.7513
3
1.7312
3
1.7393
3
1.7342
3
1.8661
2
1.7230
3
    1.7296
3
1.7169
3
  1.4281
1
   
mPW1PW91 1.7388
3
1.7673
3
1.7349
3
1.7469
3
1.7476
3
1.7270
3
1.7399
3
1.7325
3
1.8641
2
1.7192
3
    1.7247
3
1.7147
3
  1.4254
1
   
M06-2X         1.7705
3
                         
PBEPBE 1.9120
2
1.7904
3
1.7538
3
1.7638
3
1.7640
3
1.7439
3
1.7387
3
1.7421
3
1.8708
2
1.7350
3
1.4323
1
  1.7420
3
1.7232
3
1.8495
2
1.4390
1
1.4323
1
1.5401
2
PBEPBEultrafine         1.4453
1
                         
PBE1PBE         1.7476
3
                         
HSEh1PBE         1.7504
3
                         
TPSSh         1.7675
3
  1.7560
3
            1.7539
3
       
Moller Plesset perturbation MP2   1.9388
3
1.8957
3
1.9128
3
1.8204
4
1.8484
3
2.4222
3
2.0748
3
2.0073
2
1.8388
3
  1.8374
3
1.7882
3
1.4056
2
1.4039
1
1.8447
3
1.4065
1
1.4032
1
MP2=FULL   1.9374
3
1.8924
3
1.9083
3
1.8148
4
1.8426
3
2.4160
3
2.0654
3
2.0016
2
1.8197
3
    1.7848
3
1.4007
2
1.4002
1
1.4189
1
   
MP3         1.9261
3
  1.7681
3
                     
MP3=FULL         1.8031
3
  1.7769
3
                     
MP4   1.9162
3
    1.9113
3
      1.9108
2
        1.7180
3
       
B2PLYP         1.7768
3
                1.7517
3
       
Configuration interaction CID   1.9232
3
1.8816
3
1.8957
3
1.9303
3
    2.0273
3
                   
CISD   1.9090
3
1.8756
3
1.8824
3
1.9186
3
    1.9700
3
                   
Quadratic configuration interaction QCISD   1.9050
3
1.8643
3
1.8789
3
1.9023
3
1.8155
3
2.4117
3
1.8988
3
1.9112
2
1.7981
3
    1.7502
3
1.7237
3
       
QCISD(T)         1.8949
3
              1.9063
2
1.8705
2
  1.8972
2
1.8271
2
 
Coupled Cluster CCD   1.9202
3
1.8718
3
1.8931
3
1.9178
3
1.8275
3
2.4226
3
1.9628
3
1.9217
2
1.8106
3
    1.7530
3
1.8840
2
  1.9491
2
1.8465
2
 
CCSD         1.9028
3
                         
CCSD(T)         2.1047
2
          1.4226
1
  1.7455
3
1.7180
3
  1.7401
3
1.6891
3
 
CCSD(T)=FULL         1.4599
2
              1.4231
1
1.4095
1
  1.4249
1
1.4059
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 2.4893
3
  2.3571
3
  2.2171
3
2.6216
3
density functional B1B95 1.4575
1
         
B3LYP 1.8403
3
  1.7735
3
  1.8122
3
1.8349
3
Moller Plesset perturbation MP2 2.4457
3
  2.1988
3
  2.1384
3
2.6471
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.