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III.G.1.a.

Comparison of levels of theory for O-O


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 1.1964
19
PM3 1.3185
28
PM6 1.3219
38
composite G2 1.3393
38
G3 1.3357
39
G3B3 1.3702
41
G4 1.3778
34
CBS-Q 1.3274
37

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) 6-311+G(3df,2pd) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z cc-pCVDZ cc-pCVTZ aug-cc-pCVTZ Sadlej_pVTZ
hartree fock HF 1.3850
38
1.4252
38
1.4248
37
1.3937
37
1.3198
69
1.3395
38
1.3346
40
1.3217
39
1.3263
38
1.3302
38
1.2840
11
1.1579
1
1.3265
44
1.3262
39
1.3308
39
1.2671
28
1.2856
35
1.2812
38
1.2361
18
1.2737
1
    1.1594
1
1.1640
1
ROHF 1.2962
10
1.4259
19
1.4149
20
1.3846
19
1.3260
21
1.3408
19
1.3400
19
1.3303
19
1.3359
17
1.2234
10
1.1508
1
1.1579
1
1.1565
2
1.3338
19
1.3315
19
1.2049
13
1.2264
15
1.2237
15
1.2092
12
      1.1594
1
 
density functional LSDA 1.4302
37
1.4638
38
1.4643
38
1.4461
36
1.3875
37
1.3890
37
1.3941
37
1.3810
37
1.3816
37
1.3315
35
1.2014
1
1.2014
1
1.3251
9
1.3808
37
1.3797
37
1.2602
9
1.3354
35
1.3368
23
1.2641
8
      1.2035
1
 
SVWN 1.2887
1
1.4081
33
1.3019
1
1.2562
1
1.3274
31
1.3118
11
1.3209
33
1.3019
11
1.3026
11
1.3039
11
1.2014
1
1.2014
1
1.2058
1
1.3056
11
1.3019
11
1.2028
1
1.3034
11
1.3016
11
1.2021
1
      1.2035
1
 
BLYP 1.4764
39
1.5080
39
1.5097
40
1.4866
39
1.4291
38
1.4316
39
1.4356
38
1.4488
38
1.4210
38
1.4245
38
1.2283
1
1.2283
1
1.3419
10
1.4281
40
1.4234
39
1.2295
1
1.3443
9
1.2311
1
1.2288
1
      1.2307
1
 
B1B95 1.4319
37
1.4767
38
1.4777
38
1.4462
37
1.3768
36
1.3727
37
1.3696
38
1.3648
37
1.3652
37
1.3644
34
1.1916
1
1.1916
1
1.3040
10
1.3672
37
1.3641
37
1.2537
9
1.3083
33
1.3015
23
1.2516
9
      1.1935
1
 
B3LYP 1.4583
39
1.4795
41
1.4821
40
1.4538
39
1.3741
41
1.3795
39
1.3965
40
1.3718
39
1.3908
30
1.3688
38
1.2878
8
1.2033
1
1.3689
44
1.3805
39
1.3761
39
1.2971
21
1.3354
35
1.3457
36
1.2855
18
1.1950
1
    1.2053
1
1.2123
1
B3LYPultrafine 1.2853
1
1.3005
1
1.3005
1
1.2548
1
1.3712
37
1.2145
1
1.2827
8
1.2056
1
1.2056
1
1.2064
1
1.2033
1
1.2033
1
1.1580
2
1.3242
10
1.3327
18
1.2041
1
1.3243
10
1.3767
37
1.2036
1
      1.2053
1
 
B3PW91 1.4472
30
1.4745
40
1.4758
40
1.4447
39
1.3670
38
1.3690
39
1.3678
39
1.3610
39
1.3800
30
1.3591
38
1.1967
1
1.1967
1
1.3083
10
1.3657
40
1.3659
38
1.1975
1
1.3007
9
1.1989
1
1.1971
1
      1.1986
1
 
mPW1PW91 1.4473
29
1.4498
39
1.4683
31
1.4378
39
1.3612
38
1.3674
38
1.3617
39
1.3549
39
1.3553
39
1.3533
38
1.1919
1
1.1919
1
1.3044
10
1.3621
38
1.3535
38
1.1927
1
1.3056
21
1.3134
14
1.1923
1
      1.1938
1
 
M06-2X 1.4990
14
1.5248
14
1.5248
14
1.4916
14
1.3683
35
1.4442
14
1.4431
14
1.4381
14
1.4385
14
1.4375
14
1.1877
1
1.1877
1
1.3038
11
1.4399
14
1.4379
14
1.1880
1
1.3129
12
1.3124
12
1.1877
1
      1.1896
1
 
PBEPBE 1.4638
31
1.4959
39
1.5182
31
1.4927
30
1.4103
37
1.4058
38
1.4281
37
1.4145
38
1.4116
39
1.4059
38
1.3219
9
1.2172
1
1.3268
10
1.4180
38
1.4071
38
1.2829
9
1.4162
13
1.3962
22
1.2879
8
      1.2196
1
1.2110
1
PBEPBEultrafine 1.3009
1
1.3210
1
1.3210
1
1.2747
1
1.3556
27
1.2284
1
1.2641
3
1.2200
1
1.2200
1
1.2207
1
1.2172
1
1.2172
1
1.1732
2
1.3374
10
1.3369
10
1.2187
1
1.3374
10
1.3370
10
1.2179
1
      1.2196
1
 
PBE1PBE 1.3721
9
1.3972
9
1.3972
9
1.3645
9
1.3220
32
1.3154
9
1.3149
9
1.3077
9
1.3083
9
1.3076
9
1.1916
1
1.1916
1
1.3112
9
1.3102
9
1.3086
9
1.1925
1
1.3100
9
1.3087
9
1.1921
1
      1.1937
1
 
HSEh1PBE 1.5195
13
1.5367
13
1.5367
13
1.5064
13
1.3725
35
1.4565
13
1.4547
13
1.4485
13
1.4490
13
1.4496
13
1.1918
1
1.1918
1
1.3038
10
1.4512
13
1.4490
13
1.1927
1
1.3139
11
1.3134
11
1.1922
1
      1.1938
1
 
TPSSh   1.2088
1
1.2088
1
1.1547
1
1.3783
39
1.1251
1
1.3779
39
1.1105
1
        1.1129
1
1.1144
1
1.3736
39
  1.1170
1
1.1113
1
        1.2087
1
 
Moller Plesset perturbation MP2 1.4723
26
1.5042
38
1.5055
37
1.7204
36
1.3981
44
1.4004
39
1.3966
59
1.3784
40
1.3791
40
1.3890
37
1.2184
1
1.2184
1
1.3771
45
1.3887
40
1.3776
43
1.2897
14
1.3420
34
1.3519
26
1.2735
11
1.2664
1
1.3168
4
1.3100
4
1.2237
1
1.2388
1
MP2=FULL 1.4661
27
1.5054
34
1.5217
30
1.7835
30
1.3968
44
1.3995
39
1.4001
41
1.3771
40
1.3934
31
1.3914
32
1.2156
1
1.2156
1
1.3244
10
1.3902
38
1.3855
37
1.2988
15
1.3229
22
1.3310
22
1.2760
9
1.2613
1
1.3159
4
1.3079
4
1.2215
1
 
ROMP2 1.6560
11
1.6766
12
1.7065
11
1.6207
14
1.5224
15
1.5215
15
1.5221
15
1.4992
15
1.5002
15
1.5006
15
1.2458
1
1.2458
1
1.2608
2
1.5078
15
1.5016
15
1.3069
7
1.3023
12
1.2940
9
1.2995
4
      1.2533
1
 
MP3 1.2929
1
1.2997
1
1.2997
1
1.2510
1
1.3760
37
1.2113
1
1.3775
40
1.1909
1
1.1909
1
1.1942
1
1.1887
1
1.1887
1
1.1482
2
1.1502
2
1.1440
2
1.1879
1
1.2013
1
1.1926
1
1.1880
1
      1.1919
1
 
MP3=FULL         1.3733
41
  1.3725
41
          1.0994
1
1.1019
1
1.0934
1
              1.1902
1
 
MP4 1.2851
1
1.5424
28
1.4464
3
1.4319
3
1.4162
35
1.2905
2
1.2930
2
1.3168
5
1.4052
28
1.2222
1
1.2208
1
1.2208
1
1.3545
10
1.3488
11
1.3421
27
1.2216
1
1.3583
10
1.3421
9
1.2216
1
      1.2268
1
 
MP4=FULL   1.5075
8
    1.3753
9
      1.3556
9
        1.3639
9
1.3558
9
  1.3718
9
1.3504
8
        1.2252
1
 
B2PLYP 1.2918
1
1.2862
1
1.2862
1
1.1894
1
1.3448
23
1.1412
1
1.1410
1
1.1229
1
1.1229
1
1.1271
1
    1.1258
1
1.1273
1
1.3289
28
  1.1302
1
1.1234
1
        1.2149
1
 
B2PLYP=FULL 1.2918
1
1.2862
1
1.2862
1
1.1894
1
1.1411
1
1.1411
1
1.1409
1
1.1226
1
1.1226
1
1.1267
1
    1.1257
1
1.1272
1
1.1218
1
  1.1300
1
1.1222
1
        1.2144
1
 
B2PLYP=FULLultrafine         1.3739
9
                                     
Configuration interaction CID 1.2779
1
1.4717
31
1.4722
31
1.4351
32
1.3660
39
1.2647
2
1.2652
2
1.3505
36
1.1861
1
1.1875
1
1.1823
1
1.1823
1
1.1917
1
1.2529
2
1.2462
2
1.1810
1
1.1952
1
1.1858
1
1.1810
1
      1.1849
1
 
CISD 1.2781
1
1.4766
33
1.4717
34
1.4466
33
1.3696
39
1.3293
1
1.2696
2
1.3600
33
1.1898
1
1.1908
1
1.1859
1
1.1859
1
1.1957
1
1.2575
2
1.2499
2
1.1846
1
1.1987
1
1.1893
1
1.1846
1
      1.1887
1
 
Quadratic configuration interaction QCISD 1.4173
3
1.5212
35
1.5273
30
1.4989
30
1.3946
37
1.4124
32
1.3936
37
1.3789
37
1.3811
32
1.3805
30
1.2318
3
1.1995
1
1.3244
10
1.3910
37
1.3523
32
1.1985
1
1.3301
16
1.3290
14
1.1986
1
      1.2031
1
 
QCISD(T) 1.2855
1
1.4046
2
1.4046
2
1.2850
1
1.4139
36
1.2918
2
1.3470
5
1.3114
5
1.3681
2
1.2125
1
1.2502
3
1.2093
1
1.3348
10
1.3960
29
1.3890
29
1.2090
1
1.3206
20
1.3036
9
1.2091
1
      1.2140
1
 
QCISD(TQ)   1.3334
1
1.3334
1
1.2864
1
1.2733
3
1.2311
1
1.2329
1
1.2107
1
1.2107
1
1.2130
1
1.2089
1
1.2089
1
  1.2175
1
1.2127
1
1.2083
1
1.2221
1
1.2138
1
1.2085
1
         
Coupled Cluster CCD 1.4149
3
1.4903
31
1.4912
31
1.4605
33
1.3816
39
1.3924
32
1.3841
34
1.3669
37
1.3690
30
1.3695
30
1.2204
3
1.1919
1
1.3193
10
1.3755
38
1.3653
28
1.1908
1
1.3106
25
1.3238
16
1.1909
1
      1.1952
1
 
CCSD 1.2843
1
1.3875
2
1.3875
2
1.3550
2
1.3811
37
1.2821
2
1.3263
5
1.2930
5
1.3801
3
1.2020
1
1.2285
3
1.1976
1
1.3246
10
1.4129
20
1.4044
20
1.2736
7
1.3179
12
1.3181
10
1.2006
4
      1.2011
1
 
CCSD=FULL 1.2843
1
1.3169
1
1.3169
1
1.2708
1
1.3364
10
1.2194
1
1.2207
1
1.1992
1
1.1992
1
1.2007
1
1.1951
1
1.1951
1
1.3238
10
1.3248
10
1.3158
10
1.2711
7
1.3290
10
1.3131
10
1.2169
5
      1.1993
1
 
CCSD(T) 1.2856
1
1.2943
2
1.3314
1
1.2834
1
1.4017
37
1.3302
5
1.3210
6
1.3097
5
1.2848
3
1.2116
1
1.2482
3
1.2083
1
1.3335
11
1.3988
31
1.3617
34
1.2802
10
1.3382
27
1.3227
13
1.2338
6
  1.2614
3
1.2539
3
1.2128
1
 
CCSD(T)=FULL 1.2856
1
1.3313
1
1.3313
1
1.2833
1
1.4426
23
1.2287
1
1.2304
1
1.2090
1
1.2090
1
1.2103
1
1.2058
1
1.2058
1
1.3335
10
1.4347
18
1.2520
18
1.2753
7
1.3521
15
1.2817
11
1.2154
5
  1.2605
3
1.2520
3
1.2111
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 1.3956
37
1.3500
38
1.3942
37
1.3470
38
1.3913
37
1.3913
37
ROHF 1.2167
1
1.1844
1
1.2144
1
1.1791
1
1.2073
1
1.2072
1
density functional LSDA 1.2411
2
1.1968
2
1.2373
2
1.1896
2
1.2221
2
1.2219
2
SVWN 1.2852
1
1.2392
1
1.2815
1
1.2336
1
1.2702
1
1.2698
1
BLYP 1.3038
1
1.2576
1
1.3008
1
1.2529
1
1.2996
1
1.2996
1
B1B95 1.3653
12
1.3147
12
1.2122
2
1.1689
2
1.2056
2
1.2056
2
B3LYP 1.4642
38
1.3993
38
1.4730
38
1.3957
38
1.4646
37
1.4604
38
B3LYPultrafine 1.2757
1
1.2329
1
1.2728
1
1.2282
1
1.2684
1
1.2684
1
B3PW91 1.2666
1
1.2243
1
1.2636
1
1.2192
1
1.2603
1
1.2602
1
mPW1PW91 1.2601
1
1.2188
1
1.2571
1
1.2137
1
1.2539
1
1.2538
1
M06-2X 1.2468
1
1.2089
1
1.2431
1
1.2023
1
1.2468
1
1.2466
1
PBEPBE 1.2900
1
1.2437
1
1.2870
1
1.2386
1
1.2872
1
1.2871
1
PBEPBEultrafine 1.2900
1
1.2437
1
1.2870
1
1.2387
1
1.2872
1
1.2871
1
PBE1PBE 1.2595
1
1.2180
1
1.2565
1
1.2128
1
1.2539
1
1.2538
1
HSEh1PBE 1.2608
1
1.2188
1
1.2577
1
1.2137
1
1.2547
1
1.2546
1
Moller Plesset perturbation MP2 1.4954
36
1.4176
38
1.5010
33
1.4140
38
1.4950
36
1.5036
34
MP2=FULL 1.3513
1
1.2637
1
1.3447
1
1.2587
1
1.3557
1
1.3554
1
ROMP2 1.4249
1
1.2934
1
1.4186
1
1.2895
1
1.4484
1
1.4485
1
MP3 1.2789
1
1.2307
1
1.2698
1
1.2236
1
1.2673
1
1.2667
1
MP4 1.3184
1
1.2559
1
1.3183
1
1.2529
1
1.3244
1
1.3246
1
Configuration interaction CID 1.2754
1
1.2235
1
1.2679
1
1.2169
1
1.2663
1
1.2659
1
CISD 1.2801
1
1.2268
1
1.2729
1
1.2204
1
1.2719
1
1.2714
1
Quadratic configuration interaction QCISD 1.2957
1
1.2401
1
1.2896
1
1.2344
1
1.2901
1
1.2898
1
QCISD(T) 1.3029
1
1.2478
1
1.2977
1
1.2428
1
1.2993
1
1.2990
1
QCISD(TQ) 1.3066
1
1.2498
1
1.3004
1
1.2441
1
1.3025
1
1.3021
1
Coupled Cluster CCD 1.2871
1
1.2334
1
1.2801
1
1.2273
1
1.2798
1
1.2794
1
CCSD 1.2932
1
1.2386
1
1.2871
1
1.2327
1
1.2870
1
1.2867
1
CCSD=FULL 1.2932
1
1.2386
1
1.2871
1
1.2327
1
1.2869
1
1.2865
1
CCSD(T) 1.3019
1
1.2471
1
1.2965
1
1.2420
1
1.2980
1
1.2977
1
CCSD(T)=FULL 1.3019
1
1.2471
1
1.2965
1
1.2420
1
1.2979
1
1.2975
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.