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III.G.1.a.

Comparison of levels of theory for O-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 1.8594
3
PM3 1.8145
4
PM6 1.7894
7
composite G2 1.7683
11
G3 1.7622
10
G3B3 1.8087
10
G4 1.7896
10
CBS-Q 1.7635
11

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 1.8545
11
1.9550
10
1.8005
11
1.9740
10
1.7745
12
1.7691
11
1.7601
11
1.7666
11
1.7672
11
1.7228
11
1.7808
2
1.7579
12
1.7778
11
1.7366
11
1.7323
11
1.7627
11
1.7346
11
1.7313
11
ROHF   1.9706
7
1.7747
8
1.9911
7
1.7463
8
1.7460
8
1.7403
8
1.7399
8
1.7402
8
    1.6810
1
1.7515
8
1.7164
8
1.7135
8
1.7440
8
1.7165
8
1.7133
8
density functional LSDA 1.8842
10
1.8173
10
1.8133
10
1.8909
10
1.8001
10
1.7995
10
1.7948
10
1.8026
10
1.8031
10
1.7527
10
  1.7975
3
1.8070
10
1.7751
10
  1.7990
10
1.7691
9
 
SVWN   1.8880
4
    1.8128
4
1.8021
3
1.8064
4
1.8089
3
1.8100
3
1.7538
3
    1.8122
3
1.7781
3
  1.8000
3
1.7751
3
 
BLYP 1.9213
10
1.9127
11
1.8634
11
1.9446
11
1.8512
11
1.8508
11
1.8456
11
1.8572
11
1.8575
11
1.7998
11
  1.8645
3
1.8588
11
1.8267
11
       
B1B95 1.8768
10
1.8075
10
1.8075
10
1.8812
10
1.7866
10
1.7866
10
1.7854
11
1.7885
10
1.7888
10
1.7413
10
  1.7995
3
1.7942
10
1.7601
10
  1.7833
10
1.7585
10
 
B3LYP 1.8932
11
1.8750
10
1.8339
11
1.9086
11
1.8172
11
1.8167
11
1.8104
11
1.8198
11
1.8202
11
1.7686
11
  1.8125
12
1.8241
11
1.7907
11
1.7866
11
1.8130
11
1.7888
11
1.7856
11
B3LYPultrafine         1.8114
10
              1.8431
3
1.8046
3
  1.8238
3
1.7873
10
 
B3PW91 1.8861
11
1.8666
11
1.8213
11
1.8947
11
1.8024
11
1.8019
11
1.7955
11
1.8044
11
1.8048
11
1.7560
11
  1.8089
3
1.8093
11
1.7757
11
       
mPW1PW91 1.8795
11
1.8593
11
1.8148
11
1.8871
11
1.7950
11
1.7945
11
1.7881
11
1.7965
11
1.7970
11
1.7494
11
  1.8011
3
1.8019
11
1.7682
11
  1.7862
10
1.7615
10
 
M06-2X 1.8742
3
1.8801
3
1.8251
3
1.8933
3
1.8088
4
1.7989
3
1.7910
3
1.8065
3
1.8074
3
1.7561
3
  1.7956
3
1.8102
3
1.7773
3
  1.7951
3
1.7737
3
 
PBEPBE 1.9064
11
1.8923
11
1.8420
11
1.9224
11
1.8271
11
1.8266
11
1.8213
11
1.8319
11
1.8323
11
1.7785
11
1.8573
2
1.8363
3
1.8346
11
1.8023
11
  1.8189
10
1.8007
11
 
PBEPBEultrafine         1.8537
5
              1.8481
3
1.8129
3
  1.8322
3
1.8091
3
 
PBE1PBE 1.8957
3
1.8330
3
1.8330
3
1.9100
3
1.7975
12
1.8075
3
1.7978
3
1.8132
3
1.8143
3
1.7574
3
  1.7993
3
1.8176
3
1.7793
3
  1.8000
3
1.7752
3
 
HSEh1PBE 1.8981
3
1.8943
3
1.8364
3
1.9137
3
1.8199
4
1.8098
3
1.8011
3
1.8174
3
1.8185
3
1.7600
3
  1.8034
3
1.8215
3
1.7828
3
  1.8034
3
1.7784
3
 
TPSSh   1.9169
1
1.8797
1
1.9433
1
1.8114
8
1.8631
1
1.8066
8
1.8685
1
        1.8703
1
1.7878
8
  1.8613
1
1.8407
1
 
Moller Plesset perturbation MP2 1.8831
11
1.8833
11
1.8363
11
1.9101
11
1.8153
12
1.8109
11
1.8148
13
1.8032
11
1.8038
11
1.7571
11
  1.7993
12
1.8132
11
1.7601
10
1.7658
3
1.8041
11
1.7515
9
1.7613
3
MP2=FULL 1.8830
11
1.8829
11
1.8359
11
1.9085
11
1.8124
12
1.8079
11
1.8028
11
1.8030
11
1.8036
11
1.7456
11
  1.7966
3
1.8118
11
1.7566
10
1.7630
3
1.8016
11
1.7349
8
1.7569
3
ROMP2 1.8399
4
1.7374
4
1.7374
4
1.8011
4
1.7089
4
1.7087
4
1.7069
4
1.6964
4
1.6972
4
1.6642
4
  1.7063
1
1.7103
4
1.6731
4
  1.7098
4
   
MP3         1.8073
11
  1.8003
10
                     
MP3=FULL         1.8015
8
  1.7963
8
                     
MP4 1.9059
2
1.9003
11
    1.8288
11
      1.7888
7
    1.8212
3
1.8418
3
1.7623
8
  1.8213
3
1.7861
3
 
MP4=FULL   1.9335
3
    1.8314
3
      1.8346
3
      1.8406
3
1.7889
3
  1.8189
3
1.7783
3
 
B2PLYP 1.8885
1
1.9131
1
1.8797
1
1.9491
1
1.8668
2
1.8650
1
1.8623
1
1.8662
1
1.8683
1
1.8174
1
  1.8582
1
1.8699
1
1.7850
8
  1.8625
1
1.8367
1
 
B2PLYP=FULL 1.8885
1
1.9129
1
1.8796
1
1.9486
1
1.8659
1
1.8640
1
1.8612
1
1.8660
1
1.8681
1
1.8136
1
  1.8581
1
1.8695
1
1.8363
1
  1.8617
1
1.8339
1
 
B2PLYP=FULLultrafine         1.8645
1
                         
Configuration interaction CID   1.8669
11
1.8154
10
1.8865
10
1.7931
11
    1.7783
10
                   
CISD   1.8761
11
1.8206
10
1.9004
10
1.7972
11
    1.7827
10
                   
Quadratic configuration interaction QCISD 1.9111
2
1.9092
11
1.8539
10
1.9614
9
1.8245
11
1.8238
11
1.8182
11
1.8169
11
1.8176
11
1.7613
11
  1.8266
3
1.8285
11
1.7731
11
  1.8080
10
1.7649
10
 
QCISD(T)         1.8357
11
      1.8795
2
1.8230
2
  1.8342
3
1.8365
10
1.7808
10
  1.8358
3
1.7947
3
 
Coupled Cluster CCD 1.9094
2
1.8816
11
1.8297
10
1.9066
11
1.8084
11
1.8079
11
1.8015
11
1.7996
11
1.8002
11
1.7519
11
  1.8011
3
1.8107
11
1.7627
11
  1.7922
10
1.7538
10
 
CCSD         1.8196
11
      1.8641
1
1.8086
1
  1.8190
3
1.8183
10
1.7645
10
1.7747
3
1.8215
3
1.7790
3
1.7699
3
CCSD=FULL         1.8330
3
            1.8181
3
1.8426
3
1.7809
3
1.7713
3
1.8188
3
1.7705
3
1.7647
3
CCSD(T)         1.8337
11
      1.8790
2
1.8226
2
  1.8329
3
1.8336
10
1.7789
10
1.7645
9
1.8171
10
1.7761
10
1.8029
5
CCSD(T)=FULL         1.8251
10
            1.8324
3
1.8318
10
1.7748
10
1.7852
3
1.8195
9
1.7613
9
1.8106
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 2.4747
11
  2.4083
11
  2.4698
11
2.2623
11
density functional B1B95 1.9305
2
         
B3LYP 1.9191
11
  1.9169
11
  1.9231
11
1.9121
11
Moller Plesset perturbation MP2 1.9174
11
  1.9137
11
  1.9219
11
1.9104
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.