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III.G.1.a.

Comparison of levels of theory for K-Na


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 3.8466
1
composite G2 3.6498
1
G3 3.6520
1
G3B3 3.5466
1
G4 3.5843
1
CBS-Q 3.6499
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) TZVP
hartree fock HF 2.8492
1
3.7067
1
3.7154
1
3.6854
1
3.6878
1
3.6878
1
3.6922
1
3.6900
1
3.6900
1
3.6882
1
3.7024
1
density functional LSDA 2.7993
1
2.8854
1
2.8854
1
3.4011
1
3.4047
1
  3.4044
1
3.3938
1
3.3938
1
3.3865
1
3.4305
1
SVWN   3.4206
1
    3.4047
1
3.4047
1
3.4044
1
3.3938
1
3.3938
1
3.3865
1
 
BLYP 2.8505
1
3.5090
1
3.4794
1
3.5202
1
3.5309
1
3.5309
1
3.5308
1
3.5166
1
3.5166
1
3.5148
1
3.5459
1
B1B95 2.8246
1
3.5492
1
3.5492
1
3.5097
1
3.5128
1
3.5128
1
3.5131
1
3.5164
1
3.5164
1
3.5081
1
3.5395
1
B3LYP 2.8359
1
3.5011
1
3.4742
1
3.5036
1
3.5106
1
3.5106
1
3.5108
1
3.5018
1
3.5018
1
3.5001
1
3.5266
1
B3LYPultrafine         3.5096
1
           
B3PW91 2.8421
1
3.5923
1
3.5963
1
3.5586
1
3.5598
1
3.5598
1
3.5600
1
3.5550
1
3.5550
1
3.5530
1
3.5807
1
mPW1PW91 2.8377
1
3.5894
1
3.5922
1
3.5597
1
3.5607
1
3.5607
1
3.5611
1
3.5571
1
3.5571
1
3.5547
1
3.5811
1
M06-2X 2.8089
1
3.4606
1
3.4296
1
3.3911
1
3.3892
1
3.3892
1
3.3893
1
3.3892
1
  3.3866
1
3.4142
1
PBEPBE 2.8442
1
3.5441
1
3.5374
1
3.5371
1
3.5414
1
3.5414
1
3.5414
1
3.5337
1
3.5337
1
3.5312
1
3.5615
1
HSEh1PBE 2.8330
1
3.5629
1
3.5610
1
3.5510
1
3.5515
1
3.5515
1
3.5518
1
3.5464
1
3.5464
1
3.5448
1
3.5717
1
TPSSh         3.6086
1
  3.6087
1
       
Moller Plesset perturbation MP2 2.8466
1
3.7060
1
3.6966
1
3.6802
1
3.5703
1
3.5703
1
3.5744
1
3.5325
1
3.5325
1
3.4444
1
3.7040
1
MP2=FULL 2.8310
1
3.7006
1
3.6676
1
3.6780
1
3.5570
1
3.5570
1
3.5604
1
3.5029
1
3.5029
1
3.4155
1
3.6729
1
MP3         3.5542
1
  3.5759
1
       
MP3=FULL         3.5689
1
  3.5710
1
       
MP4   3.6946
1
    3.5550
1
      3.5341
1
   
Configuration interaction CID   3.6942
1
3.6807
1
3.6725
1
3.5602
1
    3.5490
1
     
CISD   3.7085
1
3.6859
1
3.6874
1
3.5674
1
    3.5493
1
     
Quadratic configuration interaction QCISD   3.7084
1
3.6859
1
3.6881
1
3.5717
1
3.5717
1
3.5765
1
3.5575
1
3.5575
1
3.4507
1
3.7079
1
QCISD(T)         3.5719
1
          3.7079
1
Coupled Cluster CCD   3.6942
1
3.6804
1
3.6729
1
3.5603
1
3.5603
1
3.5644
1
3.5441
1
3.5441
1
3.4585
1
3.6891
1
CCSD         3.5714
1
           
CCSD(T)         3.5723
1
          3.7079
1
CCSD(T)=FULL         3.5594
1
          3.6890
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 3.7432
1
  3.6994
1
  3.7126
1
3.6827
1
density functional B3LYP 3.7071
1
  3.6677
1
  3.5889
1
3.5075
1
Moller Plesset perturbation MP2 3.7802
1
  3.7197
1
  3.7257
1
3.6707
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.