National Institute of Standards and Technology
 Computational Chemistry Comparison and Benchmark DataBase Release 18 October 2016 NIST Standard Reference Database 101
 I Introduction II Experimental data III Calculated data IV Data comparisons V Cost comparisons VI Input and output files VII Tutorials and Units VIII Links to other sites IX Feedback X Older CCCBDB versions XII Geometries XIII Vibrations XIV Reaction data XV Entropy data XVI Bibliographic data XVII Ion data XVIII Bad calculations XIX Index of properties XX H-bond dimers XXI Oddities

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# Comparison of levels of theory for F-K

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)
 semi-empirical 1.89481 2.18501 2.10561 2.12721

average calculated bond lengths (Å)
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 2.21851 2.13801 2.25021 2.18541 2.18501 2.25781 2.17691 2.17691 2.16001 2.20701 2.29701 2.24611 2.21481 2.09691 2.23131 2.13061 2.13061 2.20451 2.07741 2.07741 2.08541 2.21481 2.13061 2.20471 2.26471 2.30981 2.15801 2.30761 2.19871 2.19861 2.27501 2.14581 2.14581 2.14711 2.16601 2.26261 2.13431 2.26861 2.17411 2.17411 2.25421 2.13621 2.13621 2.13251 2.30541 2.17371 2.25321 2.13341 2.26151 2.16901 2.16901 2.24711 2.13041 2.13041 2.12751 2.24101 2.12641 2.16451 2.16451 2.24211 2.12871 2.12871 2.12401 2.15941 2.16191 2.29251 2.14721 2.29361 2.18581 2.18581 2.26061 2.13051 2.13051 2.13501 2.18501 2.16321 2.16351 2.24021 2.17481 2.24671 2.12761 2.13171 2.16601 2.24841 2.13631 2.29651 2.24841 2.26721 2.19841 2.14651 2.27801 2.16541 2.27611 2.17921 2.17811 2.27251 2.16061 2.16121 2.12741 2.35021 2.25631 2.14561 2.27601 2.17861 2.17761 2.27181 2.16021 2.16021 2.12571 2.17491 2.17551 2.17501 2.25921 2.31641 2.17991 2.17261 2.25931 2.15901 2.26741 2.17671 2.16491 2.26921 2.16311 2.27131 2.17701 2.16481 2.29091 2.16961 2.27901 2.17931 2.17931 2.26731 2.16761 2.17721 2.26231 2.16041 2.26931 2.17741 2.17651 2.26241 2.16541 2.17741 2.17741 2.17691

average calculated bond lengths (Å)
CEP-31G CEP-31G* CEP-121G CEP-121G* 2.21321 2.21781 2.27411 2.28501 2.21091 2.21411 2.22141 2.27181 2.29361 2.23661 2.24201 2.29401 2.31191
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.