National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
NIST Standard Reference Database 101
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III.G.1.a.

Comparison of levels of theory for Cl-C


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 1.7309
66
PM3 1.7190
61
PM6 1.7421
179
composite G2 1.7617
143
G3 1.7607
175
G3B3 1.7832
189
G3MP2 1.6801
1
G4 1.7716
183
CBS-Q 1.7614
155

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(D+d)Z cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ
hartree fock HF 1.8086
181
1.8470
180
1.7791
181
1.8374
181
1.7589
201
1.7608
181
1.7565
99
1.7730
181
1.7694
175
1.7595
175
1.7514
93
1.7682
195
1.7771
181
1.7590
177
1.7476
34
1.7685
163
1.7601
157
1.7508
26
1.7836
1
1.7264
55
1.7752
3
1.7823
1
  1.7713
11
ROHF   1.8925
29
1.8260
26
1.8190
23
1.7591
29
1.7591
29
1.7560
29
1.8225
29
1.8406
25
    2.0526
6
1.7666
29
1.7570
29
1.7810
10
1.7731
14
1.7625
14
1.7793
10
           
density functional LSDA 1.8287
175
1.8079
175
1.7684
175
1.8248
175
1.7577
175
1.7586
172
1.7553
175
1.7558
175
1.7559
175
1.7473
163
  1.7570
46
1.7590
175
1.7474
175
1.7223
7
1.7584
154
1.7492
58
1.7188
7
1.7627
1
1.7441
5
1.7637
3
1.7709
1
1.7616
1
 
SVWN   1.8182
158
    1.7541
155
1.7555
46
1.7449
158
1.7536
46
1.7536
46
1.7468
46
  1.7536
150
1.7573
46
1.7457
46
  1.7588
43
1.7495
42
    1.7441
5
1.7637
3
     
BLYP 1.8726
180
1.8991
181
1.8205
161
1.8827
181
1.7888
197
1.8101
181
1.8079
181
1.8069
161
1.8103
175
1.8017
175
  1.8090
46
1.8113
181
1.8019
181
  1.8160
108
1.8078
25
  1.8164
1
1.7973
5
1.8199
3
1.8247
1
1.8177
1
 
B1B95 1.8301
175
1.8140
175
1.7755
175
1.8317
175
1.7645
168
1.7633
175
1.7615
175
1.7627
175
1.7628
175
1.7572
175
  1.7643
46
1.7654
175
1.7557
175
1.7303
7
1.7634
156
1.7605
105
1.7280
7
1.7718
1
1.7510
5
1.7720
3
1.7794
1
1.7731
1
 
B3LYP 1.8474
181
1.8711
181
1.7966
181
1.8546
181
1.7847
181
1.7847
181
1.7829
185
1.7849
181
1.7804
93
1.7787
186
1.7725
86
1.7753
195
1.7872
181
1.7774
179
1.7741
25
1.7786
114
1.7727
186
1.7680
26
1.7954
1
1.7428
55
1.7953
3
1.8036
1
1.7962
1
1.7936
11
B3LYPultrafine   1.8789
31
    1.7843
172
1.7881
31
1.7709
56
1.7887
31
      1.7939
34
1.7880
43
1.7710
90
  1.7872
43
1.7716
178
    1.7397
2
       
B3PW91 1.8412
98
1.8554
178
1.7829
178
1.8392
178
1.7713
178
1.7714
178
1.7659
157
1.7700
178
1.7657
90
1.7644
172
  1.7726
46
1.7733
178
1.7642
178
  1.7782
108
1.7596
50
  1.7806
1
1.7595
5
1.7814
3
1.7887
1
1.7807
1
 
mPW1PW91 1.8348
102
1.8488
181
1.7717
107
1.8327
181
1.7656
181
1.7656
181
1.7634
180
1.7646
181
1.7645
175
1.7594
175
  1.7677
46
1.7679
181
1.7527
130
  1.7724
139
1.7657
51
  1.7755
1
1.7543
5
1.7761
3
1.7842
1
1.7759
1
 
M06-2X 1.8282
61
1.8395
60
1.7540
170
1.8264
61
1.7510
173
1.7673
61
1.7655
61
1.7671
61
1.7671
61
1.7575
86
  1.7690
46
1.7696
61
1.7563
86
  1.7704
46
1.7560
67
  1.7790
1
1.7559
5
1.7769
3
1.7858
1
1.7794
1
 
PBEPBE 1.8586
101
1.8725
175
1.7991
89
1.8527
89
1.7850
175
1.7850
175
1.7828
175
1.7843
175
1.7844
175
1.7770
172
1.7710
85
1.7853
46
1.7871
172
1.7766
173
1.7561
7
1.7900
55
1.7702
87
1.7532
7
1.7912
1
1.7553
7
1.7949
3
1.7978
1
1.7914
1
1.7946
11
PBEPBEultrafine   1.8767
31
    1.7818
132
1.7882
31
1.7851
31
1.7875
31
      1.7929
34
1.7869
43
1.7778
43
  1.7857
43
1.7790
42
    1.7409
2
       
PBE1PBE 1.8298
46
1.7698
46
1.7698
46
1.8252
46
1.7548
173
1.7617
46
1.7599
46
1.7612
46
1.7612
46
1.7564
46
  1.7658
46
1.7641
46
1.7558
46
  1.7667
43
1.7602
42
    1.7740
3
1.7742
3
     
HSEh1PBE 1.8367
61
1.8346
173
1.7734
61
1.8289
61
1.7555
169
1.7653
61
1.7529
173
1.7648
61
1.7648
61
1.7605
61
  1.7668
46
1.7680
61
1.7540
173
  1.7681
46
1.7613
44
  1.7745
1
1.7538
5
1.7755
3
1.7824
1
1.7751
1
 
TPSSh 1.8704
15
1.8756
34
1.7966
34
1.8522
34
1.7648
193
1.7852
34
1.7632
192
1.7846
34
1.7880
15
1.7573
179
  1.7898
34
1.7878
34
1.7589
192
  1.7869
34
1.7809
33
    1.7909
3
1.7909
3
     
wB97X-D 1.8505
24
1.8513
24
1.7695
196
1.8319
24
1.7626
196
1.7789
24
1.7616
196
1.7786
24
1.7620
196
1.7751
24
  1.7651
196
1.7623
196
1.7577
196
  1.7815
24
1.7578
195
             
B97D3 1.8986
3
1.8217
175
1.8039
3
1.8626
3
1.7732
175
1.7853
3
1.7791
3
1.7870
3
1.7719
175
1.7849
3
  1.7900
3
1.7886
3
1.7789
3
  1.7848
3
1.7668
175
             
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(D+d)Z cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ
Moller Plesset perturbation MP2 1.8546
101
1.8786
180
1.7863
180
1.8595
180
1.7497
199
1.7578
178
1.7564
176
1.7486
191
1.7572
175
1.7485
137
  1.7566
195
1.7690
181
1.7536
154
1.7433
11
1.7673
115
1.7545
106
1.7170
9
1.7765
1
1.7265
53
1.7745
3
1.7833
1
1.7745
1
1.7846
11
MP2=FULL 1.8529
96
1.8740
129
1.7826
102
1.8549
102
1.7569
180
1.7537
161
1.7520
161
1.7572
181
1.7535
97
1.7424
106
  1.7659
46
1.7629
134
1.7457
135
1.7379
11
1.7704
69
1.7481
88
1.7207
8
1.7741
1
1.7226
56
1.7637
3
1.7811
1
1.7707
1
1.7832
11
ROMP2 1.8596
8
1.8214
11
1.8195
8
1.8871
8
1.7490
11
1.7486
11
1.7407
11
1.7563
11
1.7725
8
1.7551
8
  1.7392
6
1.7666
11
1.7394
11
  1.7830
8
      1.7759
3
1.7745
3
     
MP3         1.7640
168
  1.7512
195
        1.7785
34
1.7810
34
1.7685
34
          1.7797
3
1.7783
3
     
MP3=FULL   1.8790
24
1.7892
24
1.8572
24
1.7524
191
1.7694
24
1.7483
177
1.7710
24
1.7701
24
1.7647
24
  1.7792
32
1.7814
32
1.7648
32
  1.7873
22
1.7706
15
    1.7731
3
1.7685
3
     
MP4 1.8517
6
1.8921
99
    1.7648
117
    1.7317
2
1.7716
79
    1.7836
41
1.7857
41
1.7685
66
  1.7906
39
1.7687
27
  1.7866
1
1.7403
2
  1.7936
1
1.7850
1
 
MP4=FULL   1.8924
40
    1.7724
40
      1.7732
41
      1.7839
41
1.7680
38
  1.7867
37
1.7261
19
             
B2PLYP 1.8499
35
1.8705
34
1.7950
35
1.8523
34
1.7618
144
1.7794
35
1.7746
36
1.7806
35
1.7803
35
1.7666
61
  1.7860
34
1.7854
35
1.7582
171
  1.7867
34
1.7670
59
    1.7872
3
1.7873
3
     
B2PLYP=FULL 1.8503
34
1.8878
35
1.7948
34
1.8520
33
1.7764
35
1.7789
34
1.7740
35
1.7801
34
1.7798
34
1.7737
34
  1.7856
34
1.7849
34
1.7739
34
  1.7860
34
1.7748
33
    1.7849
3
1.7839
3
     
B2PLYP=FULLultrafine 1.8573
24
1.8744
24
1.7916
24
1.8525
24
1.7768
105
1.7807
24
1.7785
24
1.7816
24
1.7813
24
1.7766
24
  1.7872
24
1.7869
24
1.7760
24
  1.7875
24
1.7778
23
             
Configuration interaction CID   1.8620
97
1.7864
95
1.8437
94
1.7532
161
    1.7537
103
                      1.7476
5
1.7669
3
     
CISD 1.8400
6
1.8653
94
1.7878
95
1.8463
94
1.7542
158
    1.7555
98
                      1.7482
5
1.7673
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(D+d)Z cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ
Quadratic configuration interaction QCISD 1.8512
6
1.8814
169
1.7892
101
1.8751
103
1.7604
138
1.7624
103
1.7611
109
1.7620
127
1.7590
133
1.7545
100
  1.7750
46
1.7765
100
1.7583
103
  1.7885
55
1.7631
70
  1.7854
1
1.7466
7
1.7798
3
1.7926
1
1.7826
1
 
QCISD(T)         1.7670
91
    1.7772
30
      1.7804
44
1.7861
77
1.7656
68
  1.7871
45
1.7323
25
    1.7666
5
1.7853
3
1.7958
1
1.7860
1
 
QCISD(T)=FULL         1.7475
27
  1.7467
28
          1.7609
28
1.7717
27
1.7995
1
1.7920
26
1.7116
13
1.7950
1
           
QCISD(TQ)         1.8278
1
  1.8089
1
          1.8669
1
    1.8586
1
1.8184
1
             
QCISD(TQ)=FULL         1.8232
1
  1.8050
1
          1.8621
1
    1.8550
1
               
Coupled Cluster CCD 1.8497
6
1.8747
102
1.7949
97
1.8550
96
1.7590
169
1.7587
103
1.7591
104
1.7592
109
1.7596
84
1.7586
78
  1.7716
46
1.7734
99
1.7634
78
1.6759
2
1.7816
63
1.7642
49
1.6757
2
1.7815
1
1.7587
5
1.7775
3
1.7891
1
1.7798
1
 
CCSD         1.7546
122
    1.7293
2
  1.7581
50
  1.7785
41
1.7782
66
1.7596
88
1.7312
6
1.7843
41
1.7572
52
1.7331
4
  1.7601
5
1.7789
3
     
CCSD=FULL         1.7604
66
        1.7520
51
  1.7771
41
1.7794
41
1.7542
66
1.7260
6
1.7833
39
1.7340
49
1.7140
5
  1.7734
3
1.7686
3
     
CCSD(T)   1.8327
2
    1.7631
123
1.7701
31
1.7398
5
1.7759
26
1.7443
5
1.7613
3
1.6531
1
1.7792
43
1.7853
74
1.7604
74
1.7782
8
1.7908
57
1.7687
32
1.7374
4
1.7884
1
1.7569
5
1.7848
3
1.7955
1
1.7858
1
 
CCSD(T)=FULL         1.7694
74
            1.7810
40
1.7847
66
1.7658
52
1.7677
8
1.7931
49
1.7314
22
1.7437
5
1.7864
1
1.7789
3
  1.7933
1
1.7097
2
 
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(D+d)Z cc-pV(T+d)Z aug-cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ Sadlej_pVTZ

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 1.8405
181
1.7716
172
1.8437
181
1.7715
172
1.8337
181
1.8419
181
density functional B1B95 1.8403
93
1.7775
90
       
B3LYP 1.8645
181
1.7998
172
1.8618
181
1.7985
172
1.8511
181
1.8542
181
wB97X-D 1.8435
24
1.7927
23
1.8409
24
1.7911
23
1.8318
24
1.8359
24
Moller Plesset perturbation MP2 1.8735
181
1.7764
172
1.8706
181
1.7750
172
1.8582
180
1.8754
181
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.