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III.G.1.a.

Comparison of levels of theory for K-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 PM6 2.9960
1
composite G2 2.8947
1
G3B3 2.8386
1
G4 2.8384
1

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
hartree fock HF   2.9977
1
2.8809
1
2.9666
1
2.8941
2
2.8947
1
2.9302
1
2.9120
1
2.9120
1
2.8920
1
2.9130
1
2.9918
1
density functional LSDA 2.7363
1
2.9006
1
2.7667
1
2.8698
1
2.7827
1
2.7827
1
2.8151
1
2.7573
1
2.7573
1
2.7593
1
   
SVWN   2.9006
1
    2.7827
1
  2.8148
1
         
BLYP   2.9883
1
2.8515
1
2.9513
1
2.8684
1
2.8684
1
2.9072
1
2.8572
1
2.8572
1
2.8483
1
   
B1B95         2.8376
1
             
B3LYP   2.9674
1
2.8388
1
2.9332
1
2.8526
1
2.8526
1
2.8891
1
2.8475
1
2.8475
1
2.8363
1
  2.9618
1
B3LYPultrafine         2.8525
1
             
B3PW91   2.9629
1
2.8354
1
2.9268
1
2.8439
1
2.8439
1
2.8769
1
2.8345
1
2.8345
1
2.8272
1
   
mPW1PW91   2.9545
1
2.8294
1
  2.8390
1
2.8390
1
2.8725
1
2.8307
1
2.8307
1
2.8230
1
   
M06-2X         2.8343
1
             
PBEPBE   2.9664
1
2.8330
1
2.9309
1
2.8459
1
2.8459
1
2.8811
1
2.8287
1
2.8287
1
2.8261
1
   
PBEPBEultrafine         2.8461
1
             
PBE1PBE         2.8363
1
             
HSEh1PBE         2.8371
1
             
TPSSh         2.8483
1
  2.8814
1
         
Moller Plesset perturbation MP2   3.0156
1
2.9076
1
2.9794
1
2.8714
2
2.8682
1
2.9056
1
2.8532
1
2.8532
1
2.8363
1
  3.0127
1
MP2=FULL   3.0112
1
2.8752
1
2.9793
1
2.8682
2
2.8651
1
2.9027
1
2.8472
1
       
MP3         2.8699
1
  2.8765
1
         
MP3=FULL         2.8735
1
  2.9097
1
         
MP4   3.0205
1
    2.8685
1
             
B2PLYP         2.8539
1
             
Configuration interaction CID   3.0168
1
2.9066
1
2.9797
1
2.8718
1
    2.8685
1
       
CISD   3.0184
1
2.9068
1
2.9808
1
2.8713
1
    2.8684
1
       
Quadratic configuration interaction QCISD   3.0202
1
2.9097
1
2.9822
1
2.8697
1
2.8697
1
2.9069
1
2.8636
1
       
QCISD(T)         2.8687
1
             
Coupled Cluster CCD   3.0177
1
2.9090
1
2.9806
1
2.8702
1
2.8702
1
2.9072
1
2.8633
1
       
CCSD         2.8698
1
             
CCSD(T)         2.8683
1
             
CCSD(T)=FULL         2.8653
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 3.0739
1
  3.0739
1
  3.0146
1
3.0306
1
density functional B1B95 3.0529
1
         
B3LYP 3.0694
1
  3.0694
1
  2.9821
1
2.9984
1
Moller Plesset perturbation MP2 3.0909
1
  3.0909
1
  3.0167
1
3.0384
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.