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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 Al-Cl


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 2.0920
9
PM3 2.1983
9
PM6 2.1138
17
composite G2 2.1406
15
G3 2.1406
15
G3B3 2.1487
15
G4 2.1482
17
CBS-Q 2.1400
15

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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z aug-cc-pV(T+d)Z
hartree fock HF 2.1097
15
2.2265
15
2.1357
15
2.2344
15
2.1462
17
2.1399
15
2.1559
12
2.1322
15
2.1322
15
2.1352
15
2.0650
6
2.1492
17
2.1616
15
2.1393
15
2.1492
1
2.1636
15
2.1394
15
2.1494
1
2.1339
15
2.1772
9
ROHF         2.1880
2
                             
density functional LSDA 2.1085
15
2.1479
15
2.1165
15
2.2126
15
2.1243
15
2.1243
15
2.1237
15
2.1177
15
2.1177
15
2.1154
15
  2.1655
9
2.1459
15
2.1219
15
  2.1457
15
2.1608
9
  2.1530
9
2.1528
9
SVWN   2.2090
17
2.1388
1
2.2588
1
2.1293
17
2.1627
9
2.1280
17
2.1565
9
2.1565
9
2.1540
9
  2.1001
9
2.1857
9
2.1611
9
2.1353
1
2.1852
9
2.1608
9
2.1353
1
2.1530
9
2.1528
9
BLYP 2.1434
15
2.2434
15
2.1574
15
2.2601
15
2.2099
17
2.1678
15
2.1678
15
2.1632
15
2.1632
15
2.1593
15
  2.2149
9
2.1887
15
2.1661
15
  2.1225
6
    2.2026
9
2.2026
9
B1B95 2.1163
15
2.1584
15
2.1270
15
2.2224
15
2.1321
15
2.1329
15
2.1321
15
2.1265
15
2.1265
15
2.1278
15
  2.1756
9
2.1546
15
2.1320
15
  2.1547
15
2.1728
9
  2.1666
9
2.1664
9
B3LYP 2.1277
15
2.2273
15
2.1407
15
2.2405
15
2.1491
15
2.1491
15
2.1486
15
2.1436
15
2.1863
9
2.1416
15
2.0735
6
2.1585
17
2.1701
15
2.1478
15
2.1620
1
2.1709
15
2.1477
15
2.1623
1
2.1405
15
2.1836
9
B3LYPultrafine         2.1491
15
            2.1950
9
2.2145
9
2.1479
15
  2.2149
9
2.1513
17
  2.1836
9
2.1836
9
B3PW91 2.1598
9
2.2227
15
2.1356
15
2.2327
15
2.1411
15
2.1411
15
2.1403
15
2.1342
15
2.1757
9
2.1351
15
  2.1852
9
2.1628
15
2.1402
15
  2.1002
6
    2.1751
9
2.1751
9
mPW1PW91 2.1554
9
2.2185
15
2.1707
9
2.2278
15
2.1366
15
2.1366
15
2.1357
15
2.1297
15
2.1297
15
2.1307
15
  2.1804
9
2.1583
15
2.1358
15
  2.1594
15
2.1774
9
  2.1705
9
2.1706
9
M06-2X 2.1489
9
2.2501
9
2.1874
17
2.2674
9
2.1377
17
2.1726
9
2.1723
9
2.1658
9
2.1658
9
2.1668
9
  2.1744
9
2.1962
9
2.1710
9
  2.1961
9
2.1710
9
  2.1650
9
2.1651
9
PBEPBE 2.1689
9
2.2321
15
2.1854
9
2.2925
9
2.1535
15
2.1535
15
2.1530
15
2.1477
15
2.1476
15
2.1460
15
2.0785
6
2.1978
9
2.1748
15
2.1523
15
  2.2182
9
2.1520
15
  2.1868
9
2.1865
9
PBEPBEultrafine         2.1531
15
            2.1979
9
2.2178
9
2.1945
9
  2.2183
9
2.1945
9
  2.1868
9
2.1865
9
PBE1PBE 2.1539
9
2.1694
9
2.1694
9
2.2740
9
2.1412
17
2.1765
9
2.1763
9
2.1703
9
2.1703
9
2.1707
9
  2.1796
9
2.2000
9
2.1767
9
  2.2004
9
2.1766
9
  2.1698
9
2.1697
9
HSEh1PBE 2.1550
9
2.2283
17
2.1711
9
2.2763
9
2.1428
17
2.1783
9
2.1413
17
2.1722
9
2.1722
9
2.1722
9
  2.1815
9
2.2018
9
2.1416
17
  2.2023
9
2.1782
9
  2.1713
9
2.1712
9
TPSSh   2.2696
9
2.1780
9
2.2823
9
2.1942
17
2.1842
9
2.1938
17
2.1776
9
  2.1920
17
  2.1875
9
2.2078
9
2.1941
17
  2.2084
9
2.1845
9
  2.1776
9
2.1778
9
wB97X-D     2.1910
17
  2.1925
17
  2.1922
17
  2.1892
17
    2.1943
17
2.1922
17
2.1924
17
    2.1918
17
     
B97D3   2.2481
17
    2.2036
17
      2.2166
17
              2.2028
17
     
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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z aug-cc-pV(T+d)Z
Moller Plesset perturbation MP2 2.1539
9
2.2441
15
2.1237
15
2.2575
15
2.1861
17
2.1288
15
2.1291
15
2.1820
17
2.1213
15
2.1310
15
  2.1398
17
2.1609
15
2.1375
15
2.1440
1
2.1712
15
2.1784
9
2.1459
1
2.1358
17
2.1723
9
MP2=FULL 2.1531
9
2.2438
15
2.1581
9
2.3066
9
2.1250
15
2.1249
15
2.1243
15
2.1190
15
2.1574
9
2.1567
9
  2.1721
9
2.1577
15
2.1677
9
2.1102
1
2.1664
15
2.1679
9
2.1012
1
2.1231
17
2.1560
9
MP3         2.1296
15
  2.1835
17
        2.1764
9
2.2048
9
2.1796
9
        2.1738
9
2.1748
9
MP3=FULL         2.1813
17
  2.1809
17
        2.1747
9
2.2014
9
2.1711
9
        2.1618
9
2.1607
9
MP4   2.2958
9
    2.1335
15
      2.1646
9
    2.1795
9
2.2081
9
2.1672
10
  2.2184
9
2.1615
1
  2.1757
9
2.1772
9
MP4=FULL   2.2953
9
    2.1693
9
2.1382
1
2.1412
1
2.1375
1
2.1625
9
2.1353
1
  2.1509
1
2.2045
9
2.1728
9
  2.2123
9
2.1496
1
  2.1630
9
2.1409
1
B2PLYP 2.1578
9
2.2755
9
2.1711
9
2.2922
9
2.1440
17
2.1797
9
2.1796
9
2.1736
9
2.1736
9
2.1765
9
  2.1843
9
2.2069
9
2.1780
17
  2.2110
9
2.1836
9
  2.1763
9
2.1768
9
B2PLYP=FULL 2.1576
9
2.2753
9
2.1700
9
2.2921
9
2.1784
9
2.1784
9
2.1785
9
2.1728
9
2.1728
9
2.1723
9
  2.1835
9
2.2057
9
2.1802
9
  2.2091
9
2.1801
9
  2.1721
9
2.1720
9
B2PLYP=FULLultrafine         2.0779
6
                             
Configuration interaction CID   2.2839
9
2.1652
9
2.3000
9
2.1302
15
    2.1622
9
                    2.1683
9
2.1683
9
CISD   2.2847
9
2.1656
9
2.3009
9
2.1306
15
    2.1626
9
                    2.1685
9
2.1684
9
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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z aug-cc-pV(T+d)Z
Quadratic configuration interaction QCISD   2.2486
15
2.1660
9
2.3134
9
2.1327
15
2.1726
9
2.1721
9
2.1243
15
2.1243
15
2.1740
9
  2.1789
9
2.2074
9
2.1804
9
  2.2164
9
2.1813
9
  2.1746
9
2.1752
9
QCISD(T)         2.1739
9
            2.1803
9
2.2089
9
2.1822
9
  2.2189
9
2.1612
1
  2.1762
9
2.1775
9
Coupled Cluster CCD   2.2914
9
2.1641
9
2.3095
9
2.1309
15
2.1708
9
2.1702
9
2.1617
9
2.1617
9
2.1728
9
  2.1771
9
2.2054
9
2.1792
9
  2.2145
9
2.1800
9
  2.1734
9
2.1741
9
CCSD         2.1321
15
            2.1784
9
2.2067
9
2.1800
9
2.1429
1
2.2157
9
2.1808
9
2.1448
1
2.1742
9
2.1507
1
CCSD=FULL         2.1683
9
            2.1766
9
2.2032
9
2.1713
9
2.1099
1
2.2099
9
2.1461
1
2.1011
1
2.1618
9
2.1370
1
CCSD(T)         2.1338
15
            2.1800
9
2.2084
9
2.1818
9
2.1447
1
2.2184
9
2.1832
9
2.1471
1
2.1760
9
2.1533
1
CCSD(T)=FULL         2.1698
9
            2.1781
9
2.2049
9
2.1730
9
2.1110
1
2.2123
9
2.1488
1
2.1024
1
2.1394
1
2.1399
1
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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ cc-pV(T+d)Z aug-cc-pV(T+d)Z

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 2.2313
15
2.1447
15
2.2339
15
2.1450
15
2.2275
15
2.2170
15
density functional B1B95 2.1683
6
2.0926
6
       
B3LYP 2.2498
15
2.1611
15
2.2494
15
2.1608
15
2.2439
15
2.2294
15
Moller Plesset perturbation MP2 2.2570
15
2.1424
15
2.2583
15
2.1398
15
2.2437
15
2.2347
15
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.