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III.G.1.a.

Comparison of levels of theory for B-Li


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 1.7962
2
PM3 1.8090
2
PM6 1.6028
2
composite G2 2.0370
2
G3 2.0370
2
G3B3 2.0257
2
G4 2.0158
2
CBS-Q 2.0340
2

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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pCVDZ cc-pCVTZ
hartree fock HF 1.9270
2
2.1018
2
2.1018
2
2.0807
2
1.9718
2
2.0534
2
2.0606
2
2.0306
2
2.0304
2
2.0328
2
2.0098
3
2.0492
2
2.0331
2
2.0308
2
2.0416
2
2.0333
2
2.0310
2
2.1465
1
2.1347
1
ROHF   2.1904
1
2.1904
1
2.1558
1
2.1425
1
2.1425
1
2.1586
1
2.1315
1
2.1315
1
  2.1466
1
2.1473
1
2.1354
1
2.1342
1
2.1470
1
2.1369
1
2.1347
1
2.1465
1
2.1347
1
density functional LSDA 1.9455
2
2.0744
2
2.0744
2
2.0502
2
2.0334
2
2.0322
2
2.0386
2
2.0095
2
2.0107
2
2.0129
2
2.0241
2
2.0281
2
2.0116
2
  2.0165
2
2.0108
2
  2.1406
1
2.1224
1
SVWN   2.0364
3
    1.9975
3
2.0322
2
2.0007
3
2.0095
2
2.0107
2
2.0129
2
  2.0281
2
2.0116
2
  2.0165
2
2.0108
2
  2.1406
1
2.1224
1
BLYP 1.9726
2
2.0975
2
2.0975
2
2.0742
2
2.0578
2
2.0556
2
2.0641
2
2.0375
2
2.0382
2
2.0377
2
2.0531
2
2.0565
2
2.0382
2
        2.1665
1
2.1521
1
B1B95 1.9534
2
2.0931
2
2.0931
2
1.9753
1
2.0495
2
2.0495
2
2.1642
1
2.0242
2
2.0249
2
  2.0385
2
  2.1379
1
  2.1508
1
2.1388
1
    2.1369
1
B3LYP 1.9530
2
2.0835
2
2.0835
2
2.0598
2
2.0423
2
2.0404
2
2.0481
2
2.0205
2
2.0213
2
2.0222
2
1.9998
3
2.0405
2
2.0222
2
2.0194
2
2.0310
2
2.0219
2
2.0194
2
2.1435
1
2.1296
1
B3LYPultrafine   2.1857
1
    2.0423
2
2.1417
1
2.1552
1
2.1284
1
    2.1425
1
2.0402
2
2.0222
2
  2.0310
2
2.0219
2
  2.1435
1
2.1296
1
B3PW91 1.9557
2
2.0961
2
2.0961
2
2.0716
2
2.0515
2
2.0502
2
2.0564
2
2.0268
2
2.0275
2
2.0322
2
2.0413
2
2.0490
2
2.0289
2
        2.1522
1
2.1359
1
mPW1PW91 1.9504
2
2.0918
2
2.0918
2
2.0680
2
2.0473
2
2.0458
2
2.0524
2
2.0221
2
2.0227
2
2.0279
2
2.0368
2
2.0444
2
2.0245
2
  2.0340
2
2.0244
2
  2.1473
1
2.1313
1
M06-2X 1.9373
2
2.0704
2
2.0704
2
2.0506
2
2.0034
3
2.0311
2
2.0398
2
2.0134
2
2.0131
2
2.0142
2
2.0243
2
2.0327
2
2.0153
2
  2.0241
2
2.0153
2
  2.1285
1
2.1180
1
PBEPBE 1.9679
2
2.1012
2
2.1012
2
2.0775
2
2.0584
2
2.0570
2
2.0641
2
2.0351
2
2.0358
2
2.0396
2
2.0502
2
2.0568
2
2.0368
2
  2.0461
2
2.0363
2
  2.1673
1
2.1502
1
PBEPBEultrafine   2.2113
1
    2.0583
2
2.1657
1
2.1776
1
2.1497
1
    2.1625
1
2.0566
2
2.0366
2
  2.0459
2
2.0362
2
  2.1673
1
2.1502
1
PBE1PBE 1.9485
2
2.0899
2
2.0899
2
2.0653
2
2.0129
3
2.0457
2
2.0510
2
2.0204
2
2.0210
2
2.0261
2
2.0351
2
2.0426
2
2.0229
2
  2.0321
2
2.0227
2
  2.1469
1
2.1310
1
HSEh1PBE 1.9500
2
2.0909
2
2.0909
2
2.0665
2
2.0468
2
2.0453
2
2.0521
2
2.0219
2
2.0225
2
2.0269
2
2.0366
2
2.0438
2
2.0242
2
  2.0335
2
2.0240
2
  2.1477
1
2.1321
1
TPSSh   2.1997
1
2.1997
1
2.1651
1
2.1530
1
2.1530
1
2.1642
1
2.1369
1
    2.1505
1
2.1568
1
2.1382
1
  2.1516
1
2.1391
1
  2.1530
1
2.1376
1
Moller Plesset perturbation MP2 1.9420
2
2.1075
2
2.1075
2
2.0911
2
2.0511
2
2.0498
2
2.0579
2
2.0318
2
2.0337
2
2.0359
2
2.0079
3
2.0607
2
2.0389
2
2.0349
2
2.0559
2
2.0408
2
2.0361
2
2.1588
1
2.1407
1
MP2=FULL 1.9415
2
2.1021
2
2.1021
2
2.0845
2
2.0386
2
2.0365
2
2.0403
2
2.0234
2
2.0245
2
2.0016
2
2.0383
2
2.0337
2
2.0138
2
2.0103
2
2.0184
2
2.0084
2
2.0023
2
2.1532
1
2.1280
1
ROMP2 2.0036
1
2.2078
1
2.2078
1
2.1790
1
2.1479
1
2.1479
1
2.1657
1
2.1391
1
2.1391
1
2.1370
1
2.1500
1
2.1664
1
2.1464
1
  2.1679
1
    2.1639
1
2.1454
1
MP3         2.0499
2
  2.0565
2
      2.1444
1
2.1648
1
2.1429
1
        2.1617
1
2.1419
1
MP3=FULL         2.1374
1
  2.1522
1
      2.1409
1
2.1458
1
2.1161
1
        2.1554
1
2.1288
1
MP4   2.1159
2
    2.0523
2
      2.0347
2
  2.0424
2
2.0642
2
2.0413
2
  2.0615
2
2.0437
2
  2.1645
1
2.1441
1
MP4=FULL   2.1104
2
    2.0391
2
      2.0252
2
    2.0348
2
2.0143
2
  2.0172
2
2.0085
2
  2.1584
1
2.1318
1
B2PLYP 2.0126
1
2.1882
1
2.1882
1
2.1573
1
2.0418
2
2.1384
1
2.1538
1
2.1258
1
2.1258
1
2.1237
1
2.1387
1
2.1473
1
2.1296
1
  2.1441
1
2.1314
1
  2.1440
1
2.1289
1
B2PLYP=FULL 2.0125
1
2.1880
1
2.1880
1
2.1567
1
2.1361
1
2.1361
1
2.1508
1
2.1229
1
2.1229
1
2.1133
1
2.1376
1
2.1407
1
2.1217
1
  2.1270
1
2.1202
1
  2.1420
1
2.1249
1
Configuration interaction CID   2.1130
2
2.1130
2
2.0985
2
2.0491
2
    2.0286
2
                  2.1590
1
2.1390
1
CISD   2.1181
2
2.1181
2
2.1042
2
2.0527
2
    2.0313
2
                  2.1622
1
2.1416
1
Quadratic configuration interaction QCISD   2.1205
2
2.1205
2
2.1076
2
2.0543
2
2.0524
2
2.0597
2
2.0332
2
2.0340
2
2.0377
2
2.0428
2
2.0634
2
2.0399
2
  2.0596
2
2.0415
2
  2.1641
1
2.1432
1
QCISD(T)         2.0571
2
          2.0450
2
2.0662
2
2.0429
2
  2.0632
2
2.0451
2
  2.1684
1
2.1471
1
QCISD(T)=FULL         2.1487
1
  2.1617
1
        2.1532
1
2.1210
1
2.1218
1
2.1111
1
2.1123
1
2.1153
1
2.1625
1
2.1345
1
QCISD(TQ)=FULL         2.1502
1
  2.1631
1
        2.1548
1
2.1220
1
2.1220
1
2.1125
1
2.1129
1
2.1162
1
   
Coupled Cluster CCD   2.1135
2
2.1135
2
2.0995
2
2.0495
2
2.0478
2
2.0559
2
2.0296
2
2.0311
2
2.0351
2
2.0399
2
2.0608
2
2.0377
2
  2.0575
2
2.0394
2
  2.1597
1
2.1398
1
CCSD         2.0540
2
          2.0428
2
2.0633
2
2.0398
2
2.0359
2
2.0596
2
2.0414
2
2.1423
1
2.1642
1
2.1433
1
CCSD=FULL         2.0409
2
          2.0389
2
2.0335
2
2.0132
2
2.0094
2
2.0155
2
2.0067
2
2.1115
1
2.1584
1
2.1312
1
CCSD(T)         2.0569
2
          2.0450
2
2.0662
2
2.0429
2
2.0394
2
2.0633
2
2.0452
2
2.0402
2
2.1685
1
2.1472
1
CCSD(T)=FULL         2.0434
2
          2.0409
2
2.0369
2
2.0158
2
2.1219
1
2.0185
2
2.0096
2
2.1153
1
2.1626
1
2.1346
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 2.0713
2
2.0577
2
2.0490
2
2.0410
2
2.0872
2
2.0833
2
density functional B3LYP 2.0777
2
2.0679
2
2.0611
2
2.0542
2
2.0672
2
2.0650
2
Moller Plesset perturbation MP2 2.0913
2
2.0576
2
2.0584
2
2.0326
2
2.1019
2
2.0905
2
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.