return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Calculated > Geometry > Calculated geometry > One type of bond

Comparison of levels of theory for I-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 PM3 2.5614
1

average calculated bond lengths (Å)
Methods with standard basis sets
3-21G 3-21G* 6-31G* 6-311G*
hartree fock HF 2.6412
1
2.4767
1
  2.4919
1
density functional LSDA 2.6372
1
2.4537
1
  2.4840
1
BLYP 2.7113
1
2.5267
1
  2.5684
1
B1B95 2.6448
1
2.4643
1
  2.4904
1
B3LYP 2.6786
1
2.4993
1
  2.5317
1
B3LYPultrafine 2.6794
1
2.5001
1
  2.5320
1
B3PW91 2.6583
1
2.4771
1
  2.5041
1
mPW1PW91 2.6501
1
2.4705
1
  2.4957
1
M06-2X 2.6457
1
2.4754
1
  2.4931
1
PBEPBE 2.6797
1
2.4911
1
  2.5255
1
PBEPBEultrafine 2.6803
1
2.4921
1
  2.5260
1
PBE1PBE 2.6490
1
2.4683
1
  2.4935
1
HSEh1PBE 2.6554
1
2.4734
1
  2.5006
1
wB97X-D   2.4464
1
   
B97D3 2.6915
1
     
3-21G 3-21G* 6-31G* 6-311G*
Moller Plesset perturbation MP2 2.6904
1
2.4904
1
2.5291
1
2.5151
1
MP2=FULL 2.6908
1
2.4891
1
  2.5069
1
MP4 2.7169
1
2.5075
1
  2.5266
1
B2PLYP 2.6804
1
2.4939
1
  2.5193
1
Configuration interaction CID 2.7063
1
2.4935
1
  2.4997
1
CISD 2.7105
1
2.4945
1
  2.5005
1
3-21G 3-21G* 6-31G* 6-311G*
Quadratic configuration interaction QCISD 2.7218
1
2.5053
1
  2.5218
1
QCISD(T) 2.7263
1
2.5113
1
  2.5310
1
Coupled Cluster CCD 2.7161
1
2.5031
1
  2.5185
1
CCSD 2.7215
1
2.5053
1
  2.5215
1
CCSD(T) 2.7264
1
2.5113
1
  2.5309
1
CCSD(T)=FULL 2.7266
1
2.5097
1
  2.5330
1
3-21G 3-21G* 6-31G* 6-311G*

average calculated bond lengths (Å)
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD cc-pVTZ-PP aug-cc-pVTZ-PP Def2TZVPP
hartree fock HF 2.5760
1
  2.5760
1
  2.6293
1
2.5947
1
2.4660
1
  2.4642
1
ROHF             2.4660
1
  2.4642
1
density functional LSDA 2.6159
1
  2.6159
1
  2.6601
1
2.6298
1
2.4600
1
  2.4528
1
BLYP 2.6638
1
  2.6638
1
  2.7094
1
2.6781
1
2.5402
1
  2.5349
1
B1B95 2.6046
1
  2.6045
1
  2.6515
1
2.6188
1
2.4673
1
  2.4627
1
B3LYP 2.6302
1
  2.6302
1
  2.6769
1
2.6453
1
2.5056
1
  2.5004
1
B3LYPultrafine 2.6303
1
  2.6303
1
  2.6770
1
2.6453
1
2.5056
1
  2.5004
1
B3PW91 2.6088
1
  2.6088
1
  2.6562
1
2.6228
1
2.4794
1
  2.4742
1
mPW1PW91 2.5998
1
  2.5998
1
  2.6478
1
2.6141
1
2.4711
1
  2.4662
1
M06-2X 2.5956
1
  2.5956
1
  2.6419
1
2.6117
1
2.4697
1
  2.4666
1
PBEPBE 2.6313
1
  2.6313
1
  2.6763
1
2.6452
1
2.4996
1
  2.4943
1
PBEPBEultrafine 2.6314
1
  2.6314
1
  2.6764
1
2.6452
1
2.4996
1
  2.4943
1
PBE1PBE 2.5980
1
  2.5980
1
  2.6456
1
2.6124
1
2.4687
1
  2.4639
1
HSEh1PBE 2.6024
1
  2.6024
1
  2.6496
1
2.6170
1
2.4752
1
  2.4702
1
TPSSh             2.4838
1
  2.4789
1
wB97X-D             2.4709
1
  2.4657
1
B97D3             2.5180
1
  2.5117
1
Moller Plesset perturbation MP2 2.6438
1
  2.6438
1
  2.6860
1
2.6577
1
2.4617
1
  2.4548
1
MP2=FULL 2.6438
1
  2.6438
1
  2.6860
1
2.6577
1
2.4600
1
  2.4521
1
ROMP2             2.4612
1
  2.4549
1
MP3             2.4787
1
  2.4762
1
MP3=FULL             2.4774
1
  2.4741
1
MP4 2.6773
1
  2.6773
1
  2.7237
1
2.6959
1
2.4834
1
  2.4799
1
MP4=FULL             2.4815
1
  2.4767
1
B2PLYP 2.6314
1
  2.6314
1
  2.6780
1
2.6473
1
2.4876
1
  2.4830
1
B2PLYP=FULL             2.4870
1
  2.4821
1
B2PLYP=FULLultrafine             2.4870
1
  2.4821
1
Configuration interaction CID 2.6691
1
  2.6691
1
  2.7171
1
2.6886
1
2.4629
1
  2.4525
1
CISD 2.6738
1
  2.6738
1
  2.7230
1
2.6940
1
2.4637
1
  2.4531
1
Quadratic configuration interaction QCISD 2.6825
1
  2.6825
1
  2.7313
1
2.7027
1
2.4789
1
  2.4750
1
QCISD(T) 2.6855
1
  2.6855
1
  2.7352
1
2.7067
1
2.4871
1
  2.4845
1
QCISD(T)=FULL             2.4851
1
  2.4813
1
Coupled Cluster CCD 2.6764
1
  2.6764
1
  2.7242
1
2.6958
1
2.4764
1
  2.4715
1
CCSD 2.6821
1
  2.6821
1
  2.7311
1
2.7022
1
2.4789
1
  2.4747
1
CCSD=FULL             2.4769
1
  2.4716
1
CCSD(T) 2.6856
1
  2.6856
1
  2.7354
1
2.7067
1
2.4871
1
  2.4845
1
CCSD(T)=FULL 2.6856
1
  2.6856
1
  2.7354
1
2.7067
1
2.4852
1
  2.4813
1
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.