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III.G.1.a.

Comparison of levels of theory for As-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 PM3 1.6199
2
PM6 1.7040
3
composite G2 1.6070
3
G3 1.6072
2
G3B3 1.6486
3
G4 1.6328
1
CBS-Q 1.6134
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) TZVP cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 1.6177
3
1.6453
3
1.6368
3
1.6659
3
1.6032
4
1.6065
3
1.6012
3
1.5963
3
1.5963
3
1.5909
2
1.5968
3
1.6087
3
1.5908
3
1.6120
3
1.5920
3
ROHF   1.6456
3
1.6369
3
1.6662
3
1.6065
3
1.6065
3
1.6011
3
1.5963
3
1.5963
3
  1.6032
2
1.6087
3
1.5907
3
1.6119
3
1.5919
3
density functional LSDA 1.6435
3
1.6675
3
1.6675
3
1.6898
3
1.6447
3
1.6447
3
1.6394
3
1.6348
3
1.6348
3
1.6241
2
1.6372
2
1.6485
3
1.6312
2
1.6500
3
1.6321
2
SVWN   1.6665
2
    1.6475
2
1.6475
2
1.6423
2
1.6379
2
1.6379
2
1.6241
2
  1.6516
2
1.6312
2
1.6535
2
1.6321
2
BLYP 1.6708
3
1.6922
3
1.6975
3
1.7238
3
1.6759
3
1.6759
3
1.6713
3
1.6700
3
1.6700
3
1.6528
3
1.6750
2
1.6823
3
1.6623
3
   
B1B95 1.6430
3
1.6592
3
1.6592
3
1.6825
3
1.6355
3
1.6355
3
1.6303
3
1.6272
3
1.6272
3
1.6154
3
1.6303
2
1.6385
3
1.6201
3
1.6405
3
1.6210
3
B3LYP 1.6489
3
1.6706
3
1.6728
3
1.6970
3
1.6497
3
1.6497
3
1.6452
3
1.6419
3
1.6419
3
1.6285
3
1.6419
3
1.6541
3
1.6352
3
1.6562
3
1.6362
3
B3LYPultrafine         1.6495
3
            1.6586
2
1.6396
2
1.6611
2
1.6377
3
B3PW91 1.6492
3
1.6669
3
1.6673
3
1.6903
3
1.6429
3
1.6429
3
1.6375
3
1.6346
3
1.6346
3
1.6219
3
1.6378
2
1.6466
3
1.6275
3
   
mPW1PW91 1.6443
3
1.6623
3
1.6623
3
1.6851
3
1.6377
3
1.6377
3
1.6323
3
1.6290
3
1.6290
3
1.6170
3
1.6322
2
1.6409
3
1.6222
3
1.6426
3
1.6230
3
M06-2X 1.6493
2
1.6618
2
1.6577
2
1.6812
2
1.6280
2
1.6280
2
1.6235
2
1.6225
2
1.6225
2
1.6093
2
1.6226
2
1.6299
2
1.6164
2
1.6335
2
1.6176
2
PBEPBE 1.6677
3
1.6864
3
1.6892
3
1.7133
3
1.6653
3
1.6653
3
1.6599
3
1.6587
3
1.6587
3
1.6425
3
1.6621
2
1.6705
3
1.6504
3
1.6718
3
1.6514
3
PBEPBEultrafine         1.6684
2
            1.6742
2
1.6542
2
1.6761
2
1.6554
2
PBE1PBE 1.6635
2
1.6660
2
1.6660
2
1.6913
2
1.6376
3
1.6412
2
1.6358
2
1.6329
2
1.6329
2
1.6190
2
1.6323
2
1.6449
2
1.6258
2
1.6470
2
1.6269
2
HSEh1PBE 1.6649
2
1.6688
2
1.6679
2
1.6935
2
1.6432
2
1.6432
2
1.6379
2
1.6351
2
1.6351
2
1.6209
2
1.6346
2
1.6472
2
1.6282
2
1.6495
2
1.6293
2
TPSSh         1.6570
3
  1.6513
3
          1.6381
3
   
Moller Plesset perturbation MP2 1.6484
3
1.6746
3
1.6731
3
1.6966
3
1.6491
3
1.6491
3
1.6463
3
1.6367
3
1.6367
3
1.6272
3
1.6349
3
1.6481
3
1.6256
3
1.6547
3
1.6283
3
MP2=FULL 1.6481
3
1.6740
3
1.6731
3
1.6953
3
1.6463
3
1.6463
3
1.6431
3
1.6338
3
1.6338
3
1.6190
3
1.6275
2
1.6474
3
1.6220
3
1.6535
3
1.6228
3
ROMP2 1.6668
3
1.6925
3
1.6925
3
1.7193
3
1.6667
3
1.6667
3
1.6635
3
1.6545
3
1.6544
3
1.6431
3
1.6574
2
1.6664
3
1.6437
3
1.6754
3
 
MP3         1.6287
3
  1.6323
3
          1.6001
1
   
MP3=FULL         1.6334
3
  1.6291
3
               
MP4   1.7137
3
    1.6798
3
      1.6694
3
  1.6556
2
1.6700
2
1.6509
3
1.6744
2
1.6449
2
MP4=FULL   1.7033
2
    1.6643
2
      1.6547
2
    1.6690
2
1.6377
2
1.6727
2
1.6393
2
B2PLYP                         1.6397
1
   
Configuration interaction CID   1.6553
3
1.6504
3
1.6760
3
1.6248
3
    1.6101
3
             
CISD   1.6653
3
1.6587
3
1.6877
3
1.6302
3
    1.6148
2
             
Quadratic configuration interaction QCISD   1.7000
3
1.6928
3
1.7326
3
1.6541
3
1.6541
3
1.6480
3
1.6429
3
1.6429
3
1.6281
3
1.6428
2
1.6580
3
1.6275
3
1.6626
3
1.6296
3
QCISD(T)         1.6647
3
          1.6512
2
1.6666
3
1.6320
3
1.6730
2
1.6416
2
Coupled Cluster CCD   1.6616
3
1.6580
3
1.6828
3
1.6338
3
1.6338
3
1.6302
3
1.6192
3
1.6192
3
1.6111
3
1.6176
2
1.6315
3
1.6091
3
1.6378
3
1.6112
3
CCSD         1.6470
3
          1.6331
2
1.6463
3
1.6200
3
1.6546
2
1.6247
2
CCSD=FULL         1.6459
2
          1.6333
2
1.6472
2
1.6185
2
1.6531
2
1.6193
2
CCSD(T)         1.6603
3
          1.6453
2
1.6611
3
1.6332
3
1.6661
3
1.6356
3
CCSD(T)=FULL         1.6574
3
          1.6456
2
1.6602
3
1.6295
3
1.6645
3
1.6300
3

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 1.6747
3
  1.6747
3
  1.6721
3
1.6639
3
density functional B3LYP 1.7054
3
  1.7050
3
  1.7020
3
1.6928
3
Moller Plesset perturbation MP2 1.7082
3
  1.7094
3
  1.7076
3
1.7008
3
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.