return to home page

III.G.1.a.

Comparison of levels of theory for P-As


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 1.8094
1
PM6 1.7656
1
composite G2 1.9232
1
G3 1.9393
1
G3B3 2.0181
1
CBS-Q 1.9234
1

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
hartree fock HF 1.8935
1
2.0275
1
1.9615
1
2.0088
1
1.9532
1
1.9532
1
1.9532
1
1.9614
1
1.9614
1
1.9484
1
1.9647
1
1.9654
1
1.9607
1
1.9581
1
1.9693
1
1.9610
1
1.9581
1
density functional LSDA 1.9296
1
2.0000
1
2.0000
1
2.0457
1
1.9934
1
1.9934
1
1.9925
1
1.9982
1
1.9982
1
1.9824
1
2.0013
1
2.0067
1
1.9947
1
  2.0074
1
1.9941
1
 
SVWN   2.0625
1
    1.9934
1
1.9934
1
1.9925
1
1.9982
1
1.9982
1
1.9824
1
  2.0067
1
1.9947
1
  2.0074
1
1.9941
1
 
BLYP 1.9506
1
2.0975
1
2.0325
1
2.0805
1
2.0272
1
2.0272
1
2.0267
1
2.0345
1
2.0345
1
2.0140
1
2.0356
1
2.0396
1
2.0288
1
       
B1B95 1.9251
1
1.9881
1
1.9881
1
2.0338
1
1.9797
1
1.9797
1
1.9790
1
1.9879
1
1.9879
1
1.9720
1
1.9902
1
1.9930
1
1.9848
1
  1.9944
1
1.9847
1
 
B3LYP 1.9342
1
2.0705
1
2.0063
1
2.0538
1
2.0000
1
2.0000
1
1.9989
1
2.0068
1
2.0068
1
1.9891
1
2.0087
1
2.0121
1
2.0025
1
2.0000
1
2.0136
1
2.0023
1
2.0000
1
B3LYPultrafine         1.9992
1
            2.0120
1
2.0023
1
  2.0135
1
2.0021
1
 
B3PW91 1.9318
1
2.0650
1
2.0000
1
2.0450
1
1.9908
1
1.9908
1
1.9900
1
1.9976
1
1.9976
1
1.9816
1
2.0000
1
2.0038
1
1.9947
1
       
mPW1PW91 1.9277
1
2.0598
1
1.9946
1
2.0396
1
1.9852
1
1.9852
1
1.9845
1
1.9922
1
1.9922
1
1.9766
1
1.9949
1
1.9981
1
1.9896
1
  2.0000
1
1.9895
1
 
M06-2X 1.9175
1
2.0542
1
1.9879
1
2.0294
1
1.9769
1
1.9769
1
1.9761
1
1.9859
1
1.9859
1
1.9709
1
1.9907
1
1.9898
1
1.9852
1
  1.9920
1
1.9849
1
 
PBEPBE 1.9444
1
2.0888
1
2.0223
1
2.0676
1
2.0135
1
2.0135
1
2.0127
1
2.0212
1
2.0212
1
2.0023
1
2.0231
1
2.0264
1
2.0169
1
  2.0275
1
2.0167
1
 
PBEPBEultrafine         2.0134
1
            2.0263
1
2.0167
1
  2.0274
1
2.0166
1
 
PBE1PBE 1.9268
1
1.9952
1
1.9952
1
2.0402
1
1.9855
1
1.9855
1
1.9848
1
1.9929
1
1.9929
1
1.9769
1
1.9955
1
1.9984
1
1.9902
1
  2.0000
1
1.9901
1
 
HSEh1PBE 1.9278
1
2.0622
1
1.9971
1
2.0427
1
1.9877
1
1.9877
1
1.9870
1
1.9950
1
1.9950
1
1.9789
1
1.9977
1
2.0008
1
1.9923
1
  2.0022
1
1.9922
1
 
Moller Plesset perturbation MP2 2.0319
1
2.1839
1
2.0437
1
2.1468
1
2.0408
1
2.0408
1
2.0395
1
2.0460
1
2.0460
1
2.0245
1
2.0426
1
2.0545
1
2.0296
1
2.0207
1
2.0583
1
2.0303
1
2.0189
1
MP2=FULL 2.0313
1
2.1848
1
2.0417
1
2.1459
1
2.0351
1
2.0351
1
2.0338
1
2.0396
1
2.0396
1
2.0051
1
2.0448
1
2.0523
1
2.0233
1
2.0160
1
2.0562
1
2.0196
1
2.0119
1
MP3         2.0000
1
                       
MP4   2.1545
1
    2.0388
1
      2.0461
1
  2.0468
1
2.0545
1
2.0337
1
  2.0592
1
2.0337
1
 
MP4=FULL   2.1551
1
    2.0342
1
      2.0435
1
    2.0523
1
2.0276
1
  2.0569
1
2.0231
1
 
Configuration interaction CID   2.0837
1
1.9943
1
2.0620
1
1.9904
1
    1.9943
1
                 
CISD   2.0866
1
1.9967
1
2.0645
1
1.9930
1
    1.9972
1
                 
Quadratic configuration interaction QCISD   2.1167
1
2.0169
1
2.0908
1
2.0133
1
2.0133
1
2.0124
1
2.0177
1
2.0177
1
1.9983
1
2.0168
1
2.0255
1
2.0026
1
  2.0287
1
2.0023
1
 
QCISD(T)         2.0278
1
          2.0327
1
2.0418
1
2.0195
1
  2.0458
1
2.0197
1
 
Coupled Cluster CCD   2.1100
1
2.0111
1
2.0849
1
2.0073
1
2.0073
1
2.0064
1
2.0108
1
2.0108
1
1.9927
1
2.0101
1
2.0198
1
1.9963
1
  2.0230
1
1.9964
1
 
CCSD         2.0111
1
          2.0146
1
2.0235
1
2.0010
1
1.9911
1
2.0267
1
2.0007
1
1.9895
1
CCSD=FULL         2.0065
1
          2.0160
1
2.0216
1
1.9957
1
1.9870
1
2.0248
1
1.9921
1
1.9837
1
CCSD(T)         2.0267
1
          2.0315
1
2.0407
1
2.0183
1
2.0085
1
2.0448
1
2.0186
1
2.0069
1
CCSD(T)=FULL         2.0220
1
          2.0334
1
2.0387
1
2.0132
1
2.0042
1
2.0428
1
2.0096
1
2.0013
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 2.0363
1
  2.0353
1
  2.0413
1
2.0236
1
density functional B3LYP 2.0892
1
  2.0885
1
  2.0952
1
2.0705
1
Moller Plesset perturbation MP2 2.1952
1
  2.1939
1
  2.1992
1
2.1760
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.