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III.G.1.a.

Comparison of levels of theory for Cl-Si


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 1.9996
10
PM3 2.0207
24
PM6 2.0170
24
composite G2 2.0465
20
G3 2.0436
24
G3B3 2.0619
24
G4 2.0476
24
CBS-Q 2.0430
22

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 cc-pV(T+d)Z
hartree fock HF 2.0819
23
2.1572
24
2.0328
24
2.1648
24
2.0419
51
2.0437
24
2.0433
24
2.0412
24
2.0414
24
2.0403
24
2.0415
13
2.0534
24
2.0629
24
2.0436
24
2.0412
14
2.0668
24
2.0433
24
2.0324
10
2.0363
21
ROHF   2.2424
1
2.0764
1
  2.0898
1
2.0898
1
2.0902
1
2.0900
1
        2.1136
1
2.0866
1
         
density functional LSDA 2.0900
24
2.1028
24
2.0269
24
2.1562
24
2.0420
24
2.0421
24
2.0418
24
2.0369
24
2.0371
24
2.0317
24
  2.0498
3
2.0586
24
2.0359
24
2.0017
5
2.0596
24
2.0194
8
1.9993
5
 
SVWN   2.1428
24
    2.0403
23
2.0450
3
2.0416
24
2.0388
3
2.0390
3
2.0357
3
    2.0606
3
2.0395
3
  2.0611
3
2.0400
3
   
BLYP 2.1258
23
2.1923
24
2.0670
24
2.2053
24
2.0841
24
2.0844
24
2.0849
24
2.0823
24
2.0825
24
2.0750
24
  2.0933
3
2.1013
24
2.0796
24
  2.1092
13
     
B1B95 2.0931
24
2.0937
24
2.0299
24
2.1598
24
2.0418
24
2.0431
24
2.0426
24
2.0393
24
2.0397
24
2.0373
24
  2.0520
3
2.0604
24
2.0395
24
2.0070
5
2.0615
24
2.0307
11
2.0048
5
 
B3LYP 2.1082
24
2.1697
24
2.0473
24
2.1818
24
2.0627
24
2.0628
24
2.0627
24
2.0598
24
2.0530
11
2.0547
24
2.0540
13
2.0696
24
2.0800
24
2.0576
24
2.0475
10
2.0854
20
2.0615
20
2.0461
10
2.0495
21
B3LYPultrafine         2.0626
24
  2.0891
4
          2.0822
3
2.0691
11
  2.0837
3
2.0478
22
   
B3PW91 2.1004
11
2.1590
24
2.0387
24
2.1695
24
2.0518
24
2.0520
24
2.0515
24
2.0477
24
2.0402
11
2.0446
24
  2.0629
3
2.0691
24
2.0486
24
  2.0785
13
     
mPW1PW91 2.0885
12
2.1536
24
2.0290
13
2.1639
24
2.0467
24
2.0469
24
2.0464
24
2.0428
24
2.0430
24
2.0404
24
  2.0581
3
2.0640
24
2.0465
20
  2.0730
16
2.0498
3
   
M06-2X 2.0834
3
2.1309
3
2.0324
3
2.1490
3
2.0455
24
2.0493
3
2.0490
3
2.0446
3
2.0447
3
2.0447
3
  2.0559
3
2.0653
3
2.0467
3
  2.0674
3
2.0474
3
   
PBEPBE 2.1120
11
2.1728
24
2.0455
11
2.1807
11
2.0661
24
2.0663
24
2.0663
24
2.0631
24
2.0633
24
2.0580
24
2.0573
13
2.0760
3
2.0836
21
2.0622
24
2.0285
5
2.0872
3
2.0748
12
2.0259
5
2.0854
1
PBEPBEultrafine         2.0734
24
              2.0854
3
2.0666
3
  2.0872
3
2.0675
3
   
PBE1PBE 2.0905
3
2.0367
3
2.0367
3
2.1562
3
2.0461
24
2.0503
3
2.0501
3
2.0461
3
2.0461
3
2.0453
3
  2.0575
3
2.0665
3
2.0487
3
  2.0684
3
2.0493
3
   
HSEh1PBE 2.0918
3
2.1448
3
2.0379
3
2.1583
3
2.0478
24
2.0521
3
2.0518
3
2.0475
3
2.0474
3
2.0463
3
  2.0590
3
2.0681
3
2.0499
3
  2.0699
3
2.0505
3
   
TPSSh         2.0217
21
  2.0215
21
            2.0197
21
         
Moller Plesset perturbation MP2 2.0954
11
2.1839
24
2.0266
24
2.1944
24
2.0405
30
2.0388
24
2.0430
40
2.0354
21
2.0341
24
2.0380
23
  2.0487
24
2.0640
24
2.0453
26
2.0179
6
2.0809
17
2.0379
10
2.0299
5
2.0343
21
MP2=FULL 2.0949
11
2.1902
20
2.0201
13
2.1903
13
2.0382
30
2.0365
24
2.0358
24
2.0334
24
2.0257
11
2.0218
11
  2.0515
3
2.0644
20
2.0330
17
2.0118
6
2.0905
9
1.9947
6
1.9986
5
2.0252
21
MP3         2.0413
24
  2.0141
21
                       
MP3=FULL         2.0131
21
  2.0124
21
                       
MP4   2.1911
13
    2.0489
20
    2.0733
2
2.0347
11
    2.0599
3
2.0731
3
2.0601
4
         
MP4=FULL   2.1809
3
    2.0486
3
      2.0422
3
      2.0705
3
2.0456
3
         
B2PLYP         2.0508
21
                2.0194
21
         
B2PLYP=FULLultrafine         2.0620
8
                           
Configuration interaction CID   2.1729
11
2.0219
13
2.1858
13
2.0389
24
    2.0342
15
                     
CISD   2.1753
11
2.0228
13
2.1881
13
2.0397
24
    2.0298
13
                     
Quadratic configuration interaction QCISD   2.1924
24
2.0274
13
2.2013
13
2.0449
24
2.0395
13
2.0471
15
2.0432
20
2.0387
21
2.0301
8
  2.0580
3
2.0749
17
2.0471
11
  2.0801
3
2.0508
3
  2.0743
1
QCISD(T)         2.0501
12
    2.0751
2
      2.0605
3
2.1072
5
2.0805
5
  2.1177
5
2.1182
2
   
Coupled Cluster CCD   2.1825
13
2.0246
13
2.1944
13
2.0424
24
2.0366
13
2.0327
11
2.0371
15
2.0244
8
2.0279
8
  2.0556
3
2.0717
17
2.0309
8
  2.0638
8
2.0305
8
   
CCSD         2.0429
21
    2.0719
2
      2.0574
3
2.0705
3
2.0491
3
  2.0794
3
     
CCSD=FULL         2.0462
3
            2.0567
3
2.0680
3
2.0430
3
         
CCSD(T)   2.2657
1
    2.0524
16
2.0781
4
2.0832
1
2.0744
2
2.0823
1
  2.0741
1
2.0602
3
2.1075
6
2.0826
8
  2.1168
5
2.1073
3
  2.0761
1
CCSD(T)=FULL         2.0763
5
            2.0594
3
2.0705
3
2.0455
3
  2.0795
3
     

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 2.1739
24
2.0574
24
2.1753
24
2.0576
24
2.1423
24
2.1585
24
density functional B1B95 2.1949
13
2.0749
12
       
B3LYP 2.2020
24
2.0789
24
2.1999
24
2.0785
24
2.1679
24
2.1793
24
Moller Plesset perturbation MP2 2.2060
24
2.0587
24
2.2063
24
2.0569
24
2.1664
24
2.1834
24
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.