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 C-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 1.3298
235
PM3 1.3150
229
PM6 1.3504
519
composite G2 1.3260
462
G3 1.3298
484
G3B3 1.3253
538
G3MP2 1.2312
16
G4 1.3174
527
CBS-Q 1.3304
388
molecular mechanics DREIDING 1.2635
3

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 daug-cc-pVTZ Sadlej_pVTZ
hartree fock HF 1.3643
496
1.3374
531
1.3392
503
1.3372
502
1.3010
583
1.3078
503
1.2956
322
1.3020
509
1.3047
496
1.3137
502
1.3065
265
1.2647
18
1.3130
571
1.3064
501
1.3027
495
1.2508
105
1.3090
473
1.3041
449
1.2421
77
1.1461
3
1.2807
4
1.2456
5
1.1202
4
1.2535
12
ROHF 1.3441
11
1.2941
52
1.2948
52
1.2942
51
1.2574
54
1.2605
53
1.2625
53
1.2588
53
1.2611
48
1.2666
13
1.1366
1
  1.2667
21
1.2581
53
1.2572
53
1.2330
32
1.2643
44
1.2578
43
1.2205
31
  1.1596
2
1.1435
3
1.1043
1
 
density functional LSDA 1.3667
513
1.3400
522
1.3402
525
1.3385
522
1.3123
518
1.3113
520
1.3144
516
1.3079
518
1.3075
517
1.3059
509
1.1647
5
1.1608
4
1.3053
173
1.3101
517
1.3075
513
1.2132
20
1.3137
484
1.2882
172
1.2002
17
  1.1364
1
1.1271
1
1.1502
4
 
SVWN 1.2257
4
1.3592
502
1.1874
4
1.1915
4
1.3347
497
1.3084
173
1.3374
501
1.3043
173
1.3048
173
1.3034
173
1.1647
5
1.1608
4
1.3373
424
1.3074
173
1.3041
173
1.1607
4
1.3057
158
1.2977
140
1.1609
4
  1.1364
1
1.1271
1
1.1502
4
 
BLYP 1.4158
496
1.3749
503
1.3624
416
1.3753
497
1.3331
597
1.3446
500
1.3485
496
1.3297
412
1.3422
491
1.3508
496
1.1770
5
1.1728
4
1.3327
170
1.3441
495
1.3407
493
1.1723
4
1.3643
251
1.3180
57
1.1726
4
  1.1990
2
1.1864
2
1.1604
4
 
B1B95 1.3744
496
1.3508
504
1.3512
502
1.3494
502
1.3217
487
1.3202
502
1.3207
507
1.3169
498
1.3173
501
1.3121
486
1.1598
5
1.1559
4
1.3054
173
1.3191
498
1.3159
495
1.2078
22
1.3161
450
1.3060
279
1.2088
21
  1.2983
4
1.2920
4
1.1465
3
 
B3LYP 1.3959
502
1.3576
533
1.3603
503
1.3598
501
1.3215
533
1.3301
500
1.3315
528
1.3228
512
1.3137
313
1.3203
550
1.3698
197
1.2879
18
1.3341
566
1.3287
491
1.3262
488
1.2605
84
1.3136
340
1.3270
518
1.2611
77
1.1700
3
1.3073
4
1.2725
5
1.1459
4
1.2772
12
B3LYPultrafine 1.2870
7
1.3369
111
1.1866
4
1.1909
4
1.3259
478
1.3092
93
1.3154
141
1.3059
93
1.1619
4
1.1641
4
1.1648
5
1.2726
16
1.3103
110
1.3126
154
1.3128
250
1.1598
4
1.3110
141
1.3137
497
1.1600
4
  1.1848
2
1.1694
3
1.1459
4
 
B3PW91 1.3730
313
1.3560
508
1.3565
505
1.3551
503
1.3214
497
1.3252
504
1.3167
417
1.3217
504
1.3087
309
1.3318
497
1.1632
5
1.1591
4
1.3104
173
1.3246
503
1.3214
501
1.1587
4
1.3425
251
1.3039
92
1.1589
4
  1.1835
2
1.1726
2
1.1447
4
 
mPW1PW91 1.3685
313
1.3524
498
1.3408
341
1.3527
497
1.3178
496
1.3216
499
1.3236
498
1.3180
499
1.3187
492
1.3285
496
1.1610
5
1.1567
4
1.3070
173
1.3197
492
1.3031
365
1.1563
4
1.3266
372
1.2958
157
1.1565
4
  1.1807
2
1.1701
2
1.1418
4
 
M06-2X 1.3633
186
1.3385
185
1.3135
444
1.3345
186
1.3335
508
1.3084
186
1.3101
186
1.3054
186
1.3056
186
1.3023
221
1.1597
5
1.1553
4
1.3072
173
1.3072
186
1.3039
221
1.1552
4
1.3073
164
1.2988
183
1.1554
4
  1.1770
2
1.1682
2
1.1387
4
 
PBEPBE 1.3838
316
1.3772
507
1.3544
312
1.3548
307
1.3432
500
1.3469
493
1.3489
505
1.3433
497
1.3343
492
1.3349
482
1.3788
202
1.4636
18
1.3233
173
1.3452
486
1.3456
491
1.2258
22
1.3204
183
1.3126
216
1.2109
21
1.1694
1
1.1964
2
1.1847
2
1.1591
4
1.2854
12
PBEPBEultrafine 1.2349
4
1.3470
105
1.1987
4
1.2022
4
1.3555
403
1.3175
93
1.3224
111
1.3143
93
1.1727
4
1.1752
4
1.1750
5
1.2820
16
1.3191
110
1.3208
154
1.3187
154
1.1708
4
1.3200
141
1.3137
145
1.1711
4
  1.1964
2
1.1847
2
1.1591
4
 
PBE1PBE 1.3714
167
1.3384
167
1.3384
167
1.3379
167
1.3329
509
1.3100
167
1.3120
167
1.3063
167
1.3068
167
1.3057
167
1.1617
5
1.1575
4
1.3075
167
1.3087
167
1.3064
167
1.1571
4
1.3066
152
1.2984
136
1.1573
4
  1.1812
2
1.1708
2
1.1427
4
 
HSEh1PBE 1.3700
186
1.3638
510
1.3372
186
1.3367
186
1.3352
501
1.3089
186
1.3379
514
1.3053
186
1.3058
186
1.3045
186
1.1613
5
1.1573
4
1.3073
173
1.3077
186
1.3339
510
1.1568
4
1.3076
164
1.2991
149
1.1570
4
  1.1812
2
1.1706
2
1.1424
4
 
TPSSh 1.3935
31
1.3513
111
1.3515
111
1.3501
111
1.3249
558
1.3202
111
1.3257
560
1.3162
111
1.3336
31
1.3256
525
1.1578
2
  1.3170
107
1.3193
111
1.3204
560
1.2499
9
1.3175
103
1.3109
97
1.2257
5
  1.1896
2
1.1736
3
1.1527
3
 
wB97X-D 1.3606
45
1.3318
45
1.3428
607
1.3328
45
1.3192
610
1.3071
45
1.3203
610
1.3021
45
1.3159
611
1.3024
45
1.1547
2
  1.3162
610
1.3202
610
1.3150
611
1.2409
12
1.3070
45
1.3151
603
1.2364
12
  1.1812
2
1.1705
2
1.1399
4
 
B97D3 1.2862
8
1.3529
585
1.2567
8
1.2567
8
1.3305
583
1.2351
8
1.2318
8
1.2291
8
1.3279
585
1.2300
8
1.1628
2
  1.2282
8
1.2333
8
1.2277
8
1.2394
6
1.2293
8
1.3272
577
1.2293
6
  1.1952
2
1.1834
2
1.1556
4
 
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 daug-cc-pVTZ Sadlej_pVTZ
Moller Plesset perturbation MP2 1.3771
312
1.3720
533
1.3742
498
1.3791
499
1.3361
593
1.3350
503
1.3365
526
1.3283
588
1.3274
494
1.3252
411
1.1723
5
1.2564
17
1.3347
569
1.3319
503
1.3188
426
1.2559
51
1.3232
323
1.3216
282
1.2602
48
1.1810
3
1.2641
11
1.2416
8
1.1546
4
1.2860
12
MP2=FULL 1.3712
306
1.3565
368
1.3573
339
1.3623
337
1.3377
517
1.3228
407
1.3272
414
1.3221
505
1.3132
308
1.3099
332
1.1702
5
1.1671
4
1.3112
182
1.3156
369
1.3144
387
1.2523
51
1.3127
198
1.2941
213
1.2521
43
1.1778
3
1.2632
11
1.2396
8
1.1501
4
1.2849
12
ROMP2 1.3975
33
1.3350
32
1.3352
32
1.3358
32
1.2922
32
1.2918
32
1.2954
32
1.2842
32
1.2848
32
1.2782
32
1.1941
1
  1.2725
20
1.2845
32
1.2822
31
1.1386
1
1.2898
30
1.2189
7
1.2539
4
  1.1945
2
1.1829
2
1.1392
1
 
MP3 1.2152
4
1.1837
4
1.1837
4
1.1900
4
1.3280
465
1.1682
4
1.3211
554
1.1573
4
1.1570
4
1.1580
4
1.1598
5
1.1545
4
1.3020
97
1.3054
97
1.3003
97
1.1533
4
1.1682
4
1.1575
4
1.1538
4
  1.1793
2
1.1673
2
1.1382
4
 
MP3=FULL   1.3492
41
1.3492
41
1.3520
41
1.3197
550
1.3147
41
1.3178
524
1.3061
41
1.3061
41
1.3026
41
1.1485
2
  1.3055
94
1.3088
94
1.3016
93
  1.3294
35
1.3129
25
    1.1787
2
1.1657
2
1.1341
4
 
MP4 1.3623
11
1.3557
231
1.2844
9
1.2809
9
1.3164
261
1.1915
5
1.1932
5
1.2365
8
1.3086
194
1.2920
11
1.1786
5
1.1754
4
1.3164
122
1.3209
127
1.3015
151
1.1744
4
1.3306
103
1.3180
76
1.1751
4
  1.2029
2
1.1829
3
1.1617
4
 
MP4=FULL 1.2582
4
1.3628
133
1.2157
4
1.2229
4
1.3201
125
1.1876
4
1.1893
4
1.1779
4
1.3105
122
1.1739
4
1.1764
5
1.1730
4
1.1785
4
1.3181
130
1.3036
98
1.1718
4
1.3273
110
1.2933
76
1.1724
4
  1.2022
2
1.1811
3
1.1566
4
 
B2PLYP 1.3770
121
1.3442
120
1.3429
121
1.3466
120
1.3463
452
1.3128
121
1.3115
127
1.3086
121
1.3079
124
1.3041
158
1.1607
4
1.1515
3
1.3110
120
1.3111
121
1.3218
484
1.1511
3
1.3128
110
1.3028
141
1.1513
3
  1.1894
2
1.1730
3
1.1486
4
 
B2PLYP=FULL 1.3825
116
1.3397
124
1.3489
116
1.3526
115
1.3109
124
1.3180
116
1.3132
124
1.3141
116
1.3144
116
1.3112
116
1.1582
2
  1.3157
116
1.3165
116
1.3132
116
  1.3177
106
1.3107
98
    1.1892
2
1.1725
3
1.1474
4
 
B2PLYP=FULLultrafine 1.3789
49
1.3583
49
1.3586
49
1.3596
49
1.3477
270
1.3258
49
1.3270
49
1.3205
49
1.3207
49
1.3188
49
1.1582
2
  1.3214
49
1.3242
49
1.3191
49
  1.3277
49
1.3168
47
    1.1892
2
1.1725
3
1.1474
4
 
Configuration interaction CID 1.2771
7
1.3405
303
1.3376
290
1.3404
289
1.3078
393
1.1680
5
1.1685
5
1.2968
296
1.2546
15
1.2672
11
1.1560
5
1.1507
4
1.1542
4
1.1647
5
1.1560
5
1.1493
4
1.1643
4
1.1534
4
1.1497
4
  1.1782
2
1.1657
2
1.1348
4
 
CISD 1.2749
8
1.3445
304
1.3399
293
1.3422
291
1.3096
394
1.2867
6
1.1768
6
1.2977
295
1.2557
15
1.2650
10
1.1575
5
1.1523
4
1.1563
4
1.1668
5
1.1577
5
1.1509
4
1.1662
4
1.1550
4
1.1512
4
  1.1816
2
1.1683
2
1.1366
4
 
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 daug-cc-pVTZ Sadlej_pVTZ
Quadratic configuration interaction QCISD 1.4262
40
1.3743
444
1.3583
305
1.3633
313
1.3203
370
1.3233
320
1.3247
318
1.3114
341
1.3174
311
1.3109
273
1.1682
5
1.1622
4
1.3169
168
1.3190
305
1.3037
248
1.1596
5
1.3198
166
1.3027
160
1.1600
5
1.1554
1
1.1914
2
1.1713
3
1.1466
4
 
QCISD(T) 1.2344
4
1.2652
8
1.2688
8
1.2691
8
1.3138
248
1.1848
5
1.2860
13
1.3384
56
1.3084
18
1.2313
7
1.1738
5
1.1679
4
1.3172
132
1.3078
189
1.3025
147
1.1667
4
1.3182
126
1.2798
92
1.1673
4
  1.1957
2
1.1772
3
1.1526
4
 
QCISD(T)=FULL         1.2982
75
  1.3060
71
      1.1632
2
    1.2974
70
1.3090
55
1.2349
16
1.3343
56
1.2699
34
1.2239
14
  1.1950
2
1.1755
3
1.1480
4
 
QCISD(TQ) 1.2260
4
1.1973
4
1.1973
4
1.2041
4
1.2665
25
1.1785
4
1.2569
22
1.1684
4
1.1682
4
1.1681
4
1.1709
5
1.1653
4
1.1683
4
1.2473
22
1.2115
15
1.1701
9
1.2311
17
1.1768
12
1.1427
2
      1.1339
2
 
QCISD(TQ)=FULL         1.2637
21
  1.2228
13
      1.1598
2
    1.2606
21
1.2307
13
1.1533
4
1.2462
13
1.1726
7
1.1449
3
      1.1289
1
 
Coupled Cluster CCD 1.4239
40
1.3534
315
1.3500
297
1.3551
306
1.3345
418
1.3158
309
1.3182
307
1.3060
302
1.3092
247
1.3068
249
1.1624
5
1.1575
4
1.3133
160
1.3138
297
1.2939
200
1.1545
5
1.3094
177
1.2845
127
1.1550
5
  1.3045
4
1.2665
5
1.1416
4
 
CCSD 1.2233
4
1.2554
8
1.2589
8
1.2605
8
1.3136
285
1.1779
5
1.2798
13
1.3111
12
1.3896
21
1.3027
104
1.1658
5
1.1602
4
1.3063
135
1.3087
177
1.3075
204
1.2210
28
1.3153
120
1.3049
128
1.1717
14
  1.1878
2
1.1686
3
1.1443
4
 
CCSD=FULL 1.2232
4
1.1928
4
1.1928
4
1.2003
4
1.3100
172
1.1734
4
1.1743
4
1.1630
4
1.1627
4
1.3023
94
1.1636
5
1.1580
4
1.3060
133
1.3108
135
1.2993
163
1.2308
30
1.3208
119
1.2844
120
1.1689
16
  1.1871
2
1.1731
2
1.1399
4
 
CCSD(T) 1.2325
4
1.2667
12
1.2666
8
1.2672
8
1.3251
250
1.3278
63
1.2703
22
1.3098
56
1.2833
21
1.2132
12
1.2286
8
1.2335
7
1.3151
128
1.3103
184
1.2951
163
1.2355
37
1.3170
151
1.2838
91
1.2377
26
1.1622
1
1.2604
7
1.1778
6
1.1568
3
 
CCSD(T)=FULL 1.2325
4
1.2007
4
1.2007
4
1.2073
4
1.3178
178
1.1793
4
1.1805
4
1.1694
4
1.1692
4
1.1665
4
1.1705
5
1.1648
4
1.3142
140
1.3116
156
1.3000
111
1.2434
34
1.3230
123
1.2699
74
1.2256
23
  1.2595
7
1.2393
8
1.1470
4
 
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 daug-cc-pVTZ 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 1.3471
504
1.3192
489
1.3456
504
1.3167
492
1.3403
505
1.3399
503
density functional LSDA 1.2169
4
1.1939
4
1.2130
4
1.1858
4
1.1991
4
1.1990
4
SVWN 1.2169
4
1.1939
4
1.2130
4
1.1858
4
1.1991
4
1.1990
4
BLYP 1.2217
4
1.1968
4
1.2183
4
1.1889
4
1.2132
4
1.2135
4
B1B95 1.3697
256
1.3400
253
1.2421
6
1.2155
6
1.2377
6
1.2378
6
B3LYP 1.3736
504
1.3440
488
1.3715
501
1.3411
490
1.3639
502
1.3637
500
B3LYPultrafine 1.2081
4
1.1847
4
1.2049
4
1.1768
4
1.2083
5
1.1988
4
B3PW91 1.2051
4
1.1825
4
1.2017
4
1.1748
4
1.1961
4
1.1962
4
mPW1PW91 1.2020
4
1.1797
4
1.1987
4
1.1721
4
1.1932
4
1.1934
4
M06-2X 1.1948
4
1.1748
4
1.1905
4
1.1652
4
1.1907
4
1.1908
4
PBEPBE 1.2178
4
1.1940
4
1.2142
4
1.1864
4
1.2097
4
1.2099
4
PBEPBEultrafine 1.2178
4
1.1940
4
1.2142
4
1.1864
4
1.2097
4
1.2100
4
PBE1PBE 1.2024
4
1.1801
4
1.1990
4
1.1726
4
1.1938
4
1.1940
4
HSEh1PBE 1.2030
4
1.1806
4
1.1998
4
1.1731
4
1.1939
4
1.1941
4
wB97X-D 1.3478
45
1.3193
45
1.3454
45
1.3152
45
1.3379
45
1.3380
45
Moller Plesset perturbation MP2 1.3962
509
1.3495
489
1.3886
507
1.3465
491
1.3853
511
1.3850
509
MP2=FULL 1.2320
4
1.1971
4
1.2256
4
1.1895
4
1.2210
4
1.2209
4
MP3 1.2110
4
1.1828
4
1.2033
4
1.1744
4
1.1983
4
1.1981
4
MP4 1.2440
4
1.2019
4
1.2388
4
1.1956
4
1.2331
4
1.2333
4
MP4=FULL 1.2440
4
1.2019
4
1.2388
4
1.1956
4
1.2330
4
1.2330
4
B2PLYP 1.2032
3
1.1767
3
1.1995
3
1.1688
3
1.1934
3
1.1936
3
Configuration interaction CID 1.2095
4
1.1791
4
1.2025
4
1.1706
4
1.1977
4
1.1975
4
CISD 1.2130
4
1.1811
4
1.2058
4
1.1726
4
1.2009
4
1.2007
4
Quadratic configuration interaction QCISD 1.2254
4
1.1912
4
1.2183
4
1.1833
4
1.2133
4
1.2131
4
QCISD(T) 1.2292
4
1.1951
4
1.2226
4
1.1878
4
1.2171
4
1.2169
4
QCISD(TQ) 1.2246
4
1.1928
4
1.2176
4
1.1851
4
1.2125
4
1.2123
4
Coupled Cluster CCD 1.2170
4
1.1857
4
1.2100
4
1.1777
4
1.2051
4
1.2049
4
CCSD 1.2213
4
1.1887
4
1.2142
4
1.1807
4
1.2093
4
1.2091
4
CCSD=FULL 1.2213
4
1.1887
4
1.2142
4
1.1807
4
1.2091
4
1.2088
4
CCSD(T) 1.2282
4
1.1943
4
1.2215
4
1.1868
4
1.2160
4
1.2159
4
CCSD(T)=FULL 1.2282
4
1.1943
4
1.2215
4
1.1868
4
1.2159
4
1.2156
4
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.