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Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
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III.G.1.a.

Comparison of levels of theory for Si-H


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 1.4526
29
PM3 1.4933
29
PM6 1.4957
54
composite G2 1.4825
49
G3 1.4825
49
G3B3 1.4998
54
G3MP2 1.4804
4
G4 1.4983
54
CBS-Q 1.4825
49

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 aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ aug-cc-pCVTZ
hartree fock HF 1.4370
46
1.4951
49
1.4811
49
1.5019
49
1.4846
53
1.4833
49
1.4817
45
1.4819
49
1.4841
49
1.4830
49
1.4767
28
1.4907
54
1.4941
49
1.4861
49
1.4842
43
1.4933
49
1.4852
49
1.4837
43
1.4748
39
1.4795
10
1.4939
5
1.4771
10
1.4765
3
ROHF 1.4610
10
1.5152
19
1.4955
19
1.5232
19
1.4979
19
1.4984
19
1.4960
19
1.4975
19
1.4994
19
1.4991
10
  1.5012
9
1.5108
19
1.5017
19
1.4969
19
1.5080
19
1.4992
19
1.4958
19
1.4843
7
1.4843
7
  1.4768
3
1.4767
3
density functional LSDA 1.4666
49
1.5174
49
1.5076
49
1.5277
49
1.5093
49
1.5084
49
1.5076
49
1.5065
49
1.5065
49
1.5051
49
  1.5144
15
1.5189
49
1.5053
49
1.5257
12
1.5156
49
1.5145
27
1.5244
12
1.4995
10
1.4994
10
  1.4929
3
1.4929
3
SVWN   1.5128
54
    1.4921
49
1.5140
15
1.4982
54
1.5118
15
1.5119
15
1.5104
15
  1.5137
51
1.5244
15
1.5104
15
  1.5213
15
1.5098
15
  1.4995
10
1.4994
10
  1.4929
3
1.4929
3
BLYP 1.4756
46
1.5202
49
1.5056
49
1.5272
49
1.5095
54
1.5067
49
1.5058
49
1.5046
49
1.5045
49
1.5031
49
  1.5124
15
1.5174
49
1.5032
49
  1.5077
26
1.5025
7
  1.4973
10
1.4971
10
  1.4916
3
1.4916
3
B1B95 1.4588
49
1.4998
49
1.4938
49
1.5122
49
1.4946
49
1.4947
49
1.4936
49
1.4930
49
1.4932
49
1.4919
49
  1.4999
15
1.5044
49
1.4925
49
1.5127
12
1.5031
46
1.4941
37
1.5113
12
1.4836
12
1.4864
10
  1.4814
3
1.4814
3
B3LYP 1.4623
49
1.5094
49
1.4953
49
1.5162
49
1.4949
47
1.4964
49
1.4954
49
1.4944
49
1.5029
29
1.4974
54
1.4841
25
1.5021
54
1.5069
49
1.4941
49
1.4919
43
1.5038
49
1.4981
54
1.4914
43
1.4818
39
1.4881
10
1.5038
5
1.4843
10
1.4831
3
B3LYPultrafine   1.5092
7
    1.4977
49
1.4959
7
1.5029
9
1.4929
7
      1.4975
14
1.5118
15
1.4905
28
  1.5088
15
1.4933
49
  1.4980
5
1.4979
5
  1.4831
3
1.4831
3
B3PW91 1.4736
29
1.5113
49
1.4976
49
1.5166
49
1.4986
49
1.4979
49
1.4969
49
1.4972
49
1.5050
29
1.4958
49
  1.5047
15
1.5081
49
1.4970
49
  1.5006
29
1.4900
13
  1.4910
10
1.4910
10
  1.4814
5
1.4858
3
mPW1PW91 1.4681
32
1.5088
49
1.5021
29
1.5142
49
1.4963
49
1.4956
49
1.4946
49
1.4952
49
1.4954
49
1.4938
49
  1.5027
15
1.5059
49
1.4954
49
  1.4997
35
1.4989
15
  1.4894
10
1.4894
10
  1.4843
3
1.4843
3
M06-2X 1.4572
15
1.5054
15
1.4938
54
1.5153
15
1.4783
54
1.4937
15
1.4928
15
1.4906
15
1.4914
15
1.4850
24
  1.4944
15
1.5031
15
1.4842
24
  1.5011
15
1.4838
24
  1.4785
12
1.4812
10
  1.4719
5
1.4762
3
PBEPBE 1.4861
29
1.5235
49
1.5170
29
1.5408
29
1.5111
49
1.5099
49
1.5090
49
1.5092
49
1.5087
49
1.5074
49
1.4983
25
1.5166
15
1.5210
48
1.5084
49
1.5290
12
1.5215
17
1.5032
37
1.5274
12
1.5029
13
1.5022
10
  1.4923
5
1.4962
3
PBEPBEultrafine   1.5239
7
    1.5062
37
1.5099
7
1.5093
7
1.5079
7
      1.5116
14
1.5255
15
1.5131
15
  1.5227
15
1.5124
15
  1.5121
5
1.5120
5
  1.4962
3
1.4962
3
PBE1PBE 1.4666
15
1.5012
15
1.5012
15
1.5240
15
1.4986
50
1.5029
15
1.5015
15
1.5016
15
1.5019
15
1.5003
15
  1.5052
15
1.5127
15
1.5020
15
  1.5109
15
1.5015
15
  1.4921
10
1.4920
10
  1.4867
3
1.4867
3
HSEh1PBE 1.4671
15
1.4986
54
1.5013
15
1.5245
15
1.4859
54
1.5026
15
1.4864
54
1.5016
15
1.5019
15
1.5003
15
  1.5052
15
1.5131
15
1.4816
50
  1.5111
15
1.5012
15
  1.4916
10
1.4915
10
  1.4862
3
1.4862
3
TPSSh 1.4658
3
1.5069
14
1.4915
14
1.5126
14
1.4961
54
1.4925
14
1.4946
54
1.4931
14
1.4861
3
1.4947
54
  1.4965
14
1.5032
14
1.4963
54
1.4838
3
1.5024
14
1.4933
14
1.4837
3
1.4882
10
1.4881
10
  1.4838
3
1.4838
3
wB97X-D 1.4632
3
1.4966
3
1.4967
54
1.5052
3
1.4970
54
1.4868
3
1.4861
3
1.4830
3
1.4962
54
1.4856
3
  1.4890
3
1.4970
3
1.4959
54
1.4829
3
1.4964
3
1.4955
54
1.4828
3
         
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 aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ aug-cc-pCVTZ
Moller Plesset perturbation MP2 1.4610
29
1.5081
49
1.4885
49
1.5168
49
1.4959
54
1.4821
49
1.4808
49
1.4920
54
1.4828
49
1.4839
46
  1.4912
54
1.4964
49
1.4866
49
1.4921
18
1.4978
48
1.4872
47
1.4844
15
1.4757
39
1.4814
10
1.4949
5
1.4772
10
1.4758
3
MP2=FULL 1.4602
29
1.5082
49
1.4938
29
1.5261
29
1.4921
49
1.4812
49
1.4798
49
1.4881
49
1.4884
29
1.4831
36
  1.4895
15
1.4959
49
1.4848
39
1.4796
18
1.4958
17
1.4919
38
1.4698
15
1.4710
39
1.4760
10
1.4946
5
1.4736
10
1.4717
3
ROMP2 1.4663
19
1.5111
19
1.4975
19
1.5312
19
1.5019
19
1.4918
19
1.4899
19
1.4988
19
1.4932
19
1.4923
19
  1.4951
7
1.5077
19
1.4971
19
1.4993
10
1.5075
19
1.5024
10
1.4989
10
1.4734
8
1.4741
8
  1.4756
3
1.4761
3
MP3         1.4961
49
  1.4865
54
        1.4866
14
1.4968
14
1.4876
14
        1.4830
10
1.4835
10
  1.4776
3
1.4781
3
MP3=FULL   1.5049
3
1.4837
3
1.5170
3
1.4992
54
1.4743
3
1.4872
54
1.4823
3
1.4731
3
1.4757
3
  1.4855
14
1.4962
14
1.4844
14
  1.4890
3
1.4774
3
  1.4788
10
1.4784
10
  1.4744
3
1.4747
3
MP4   1.5240
33
    1.4993
49
    1.4911
25
1.4932
27
    1.4939
15
1.5044
15
1.4923
19
  1.5064
15
1.4996
12
  1.4904
7
1.4909
7
  1.4798
3
1.4803
3
MP4=FULL   1.5233
15
    1.5029
15
      1.4885
15
      1.5037
15
1.4921
15
  1.5030
15
1.4910
15
  1.4867
7
1.4858
7
  1.4769
3
1.4768
3
B2PLYP 1.4526
10
1.4998
10
1.4845
10
1.5078
10
1.4807
54
1.4838
10
1.4831
10
1.4836
10
1.4828
10
1.4798
19
  1.4864
10
1.4953
10
1.4908
49
  1.4947
10
1.4807
19
  1.4726
8
1.4749
6
  1.4738
5
1.4787
3
B2PLYP=FULL 1.4526
10
1.5001
10
1.4844
10
1.5079
10
1.4876
10
1.4835
10
1.4829
10
1.4836
10
1.4826
10
1.4823
10
  1.4861
10
1.4951
10
1.4832
10
  1.4937
10
1.4830
10
  1.4736
6
1.4736
6
  1.4775
3
1.4776
3
B2PLYP=FULLultrafine 1.4611
3
1.4979
3
1.4823
3
1.5083
3
1.4863
21
1.4823
3
1.4814
3
1.4804
3
1.4801
3
1.4814
3
  1.4841
3
1.4939
3
1.4819
3
  1.4928
3
1.4818
3
           
Configuration interaction CID   1.5236
29
1.4981
29
1.5334
29
1.4952
49
    1.4924
48
          1.4913
10
        1.4809
10
1.4812
10
  1.4776
3
1.4779
3
CISD   1.5223
33
1.4989
29
1.5344
29
1.4957
49
    1.5004
29
          1.4919
10
        1.4815
10
1.4817
10
  1.4781
3
1.4783
3
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 aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ aug-cc-pCVTZ
Quadratic configuration interaction QCISD 1.4491
2
1.5190
49
1.5087
33
1.5389
29
1.5006
49
1.4905
33
1.4850
45
1.4968
49
1.4865
47
1.4901
34
  1.4944
15
1.5012
48
1.4941
38
  1.5064
15
1.4889
24
  1.4857
13
1.4861
10
  1.4751
5
1.4806
3
QCISD(T)   1.5087
2
    1.5020
46
1.4878
12
1.4869
12
1.4924
30
      1.4958
15
1.5101
29
1.5003
29
  1.5142
25
1.5025
25
  1.4872
10
1.4877
10
  1.4812
3
1.4817
3
QCISD(T)=FULL         1.4995
7
  1.4832
7
          1.4992
7
1.4876
7
1.4826
5
1.4988
7
1.4868
7
1.4805
5
1.4772
3
1.4767
3
  1.4785
3
1.4785
3
QCISD(TQ)         1.5071
5
  1.4913
5
          1.5082
5
1.4984
5
1.4949
5
1.5110
5
1.4990
5
1.4953
5
         
QCISD(TQ)=FULL         1.5069
5
  1.4905
5
          1.5074
5
1.4956
5
1.4759
4
1.5075
5
1.4945
5
1.4937
1
1.4775
3
       
Coupled Cluster CCD 1.4489
2
1.5249
33
1.5013
29
1.5375
29
1.4999
49
1.4894
33
1.4877
33
1.4965
48
1.4937
27
1.4932
27
  1.4933
15
1.5001
48
1.4973
31
  1.5114
25
1.4889
20
  1.4848
10
1.4852
10
1.4977
5
1.4843
8
1.4799
3
CCSD   1.5079
2
    1.5004
49
1.4868
12
1.4858
12
1.4914
27
  1.4793
16
  1.4943
15
1.5015
19
1.4877
28
1.5009
10
1.5063
15
1.4888
24
1.5010
10
1.4824
12
1.4859
10
  1.4750
5
1.4805
3
CCSD=FULL         1.4980
24
        1.4767
16
  1.4932
15
1.5039
15
1.4850
24
1.4887
10
1.5028
15
1.4859
21
1.4862
10
1.4782
12
1.4808
10
  1.4715
5
1.4768
3
CCSD(T)   1.5087
2
    1.5005
42
1.4817
30
1.4869
12
1.4923
30
    1.5262
1
1.4957
15
1.5083
31
1.4966
37
1.4938
13
1.5120
27
1.4965
25
1.5029
10
1.4827
18
1.4876
10
1.4996
5
1.4860
8
1.4816
3
CCSD(T)=FULL         1.5091
22
            1.4947
15
1.5022
19
1.4902
19
1.4818
13
1.5045
15
1.4965
12
1.4877
10
1.4832
10
1.4876
7
1.4994
5
1.4831
8
1.4785
3
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 aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ aug-cc-pCVTZ

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 1.5103
49
1.4959
49
1.5061
49
1.4969
49
1.4823
49
1.4918
49
density functional B1B95 1.5162
27
1.5037
30
1.5152
2
1.5062
2
1.4924
2
1.4974
2
B3LYP 1.5232
49
1.5083
49
1.5233
49
1.5103
49
1.4965
49
1.5053
49
wB97X-D 1.5216
3
1.5049
3
1.5167
3
1.5062
3
1.4905
3
1.4921
3
Moller Plesset perturbation MP2 1.5264
49
1.5062
49
1.5213
49
1.5055
49
1.4965
49
1.5041
49
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.