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III.G.1.a.

Comparison of levels of theory for F-Br


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 1.8237
7
PM3 1.7990
7
PM6 1.7761
11
composite G2 1.8415
11
G3B3 1.8910
11
G4 1.8596
11
CBS-Q 2.2811
2

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 2.3172
2
1.9662
11
1.8327
11
1.9149
10
1.8277
28
1.8415
11
1.7348
10
1.8741
11
1.8741
11
1.8000
11
1.7162
9
1.8528
11
1.8542
11
1.8416
11
1.7127
1
1.8689
11
1.9680
6
1.7126
1
ROHF         1.6693
1
                         
density functional LSDA 1.9341
11
1.8674
11
1.8165
11
1.9193
11
1.8207
11
1.8207
11
1.8295
11
1.8377
11
1.8377
11
1.7802
11
    1.8340
11
1.8067
11
  1.8301
11
2.2421
1
 
SVWN   1.8691
11
    1.8326
10
  1.8273
11
                     
BLYP 2.1035
2
1.9520
11
1.8765
11
2.0026
10
1.8830
11
1.8830
11
1.8928
11
1.9180
10
1.9180
10
1.8397
11
    1.9419
6
1.8716
11
  1.8513
9
   
B1B95 1.9488
6
1.8616
11
1.8202
11
1.9171
11
1.8216
11
1.8229
11
1.8283
11
1.8393
11
1.8393
11
1.7859
11
    1.8369
11
1.8052
11
  1.8279
11
1.9915
2
 
B3LYP 1.9835
5
1.8966
11
1.8393
11
1.9360
11
1.8429
11
1.8429
11
1.8499
11
1.8599
11
1.8599
11
1.8040
11
  1.8472
11
1.8561
11
1.8281
11
1.7713
1
1.8505
11
1.8693
6
1.7719
1
B3LYPultrafine         2.0357
2
                1.8001
3
    1.8676
11
 
B3PW91 2.0746
2
1.8878
11
1.8300
11
1.9258
11
1.8319
11
1.8319
11
1.8366
11
1.8478
11
1.8478
11
1.7937
11
    1.8451
11
1.8152
11
  1.7978
9
   
mPW1PW91 1.8869
6
1.8762
11
1.8218
11
1.9152
11
1.8232
11
1.8232
11
1.8278
11
1.8384
11
1.8384
11
1.7856
11
    1.8364
11
1.8059
11
  1.7894
9
   
M06-2X         1.8091
11
                         
PBEPBE 2.0950
2
1.9306
11
1.8561
11
1.9653
11
1.8611
11
1.8611
11
1.8694
11
1.8801
11
1.8801
11
1.8201
11
1.8166
4
  1.8754
11
1.8476
11
  1.8305
9
1.8141
4
 
PBEPBEultrafine         1.8294
7
                         
PBE1PBE         1.8216
11
                         
HSEh1PBE         1.8256
11
                         
TPSSh         1.8131
11
  1.8186
11
            1.7960
11
       
Moller Plesset perturbation MP2 2.6323
1
1.8733
11
1.8229
11
1.9155
11
1.8051
20
1.8153
11
1.8261
17
1.8256
11
1.8256
11
1.7736
11
  1.8171
11
1.8273
11
1.7805
19
1.7533
1
1.8253
11
1.9628
2
1.7509
1
MP2=FULL 2.6323
1
1.8730
11
1.8224
11
1.9143
11
1.8017
20
1.8118
11
1.8256
11
1.8260
11
1.8260
11
1.7948
6
    1.8262
11
1.7887
14
1.7520
1
1.8067
4
   
MP3         1.8089
11
  1.7953
11
                     
MP3=FULL         1.7921
11
  1.7991
11
                     
MP4   1.8917
11
    1.8275
11
      1.9622
2
        1.8322
6
       
B2PLYP         1.8330
11
                1.7912
11
       
B2PLYP=FULLultrafine         1.8095
3
                         
Configuration interaction CID   1.8548
11
1.8120
11
1.8832
11
1.7936
11
    1.8423
6
1.7852
4
                 
CISD   1.8561
11
1.8142
11
1.8932
11
1.7973
11
    1.8492
6
1.7871
4
                 
Quadratic configuration interaction QCISD   1.8871
11
1.8357
11
1.9373
11
1.8246
11
1.8246
11
1.8320
11
1.8870
6
1.8870
6
1.8195
6
    1.8664
7
1.9043
3
       
QCISD(T)         1.8309
11
              2.0251
2
1.9678
2
  1.9964
2
1.9651
2
 
Coupled Cluster CCD   1.8711
11
1.8224
11
1.9056
11
1.8089
11
1.8089
11
1.8179
11
1.8537
6
1.8537
6
1.8015
6
    1.8275
8
1.9208
2
  1.9539
2
1.9288
2
 
CCSD         1.8207
11
                         
CCSD(T)         1.7936
9
          1.7756
1
  1.9558
3
1.9007
3
  1.9282
3
1.8961
3
 
CCSD(T)=FULL         1.9888
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 1.9799
10
  1.9744
10
  1.9346
10
1.9918
10
density functional B1B95 1.9020
9
         
B3LYP 1.9590
11
  1.9561
11
  1.9545
11
1.9489
11
Moller Plesset perturbation MP2 1.9471
11
  1.9390
11
  1.9377
11
1.9314
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.