III.G.1.a.

Comparison of levels of theory for F-S

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	1.8902 12
	PM3	1.5528 21
	PM6	1.5647 26
composite	G2	1.5686 27
	G3	1.5677 28
	G3B3	1.6114 26
	CBS-Q	1.5745 22

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(D+d)Z	cc-pV(T+d)Z	aug-cc-pV(T+d)Z
hartree fock	HF	1.6495 26	1.6316 28	1.5669 28	1.6860 28	1.5613 27	1.5666 28	1.5694 28	1.5628 28	1.5628 28	1.5427 28	1.5442 14	1.5992 32	1.5849 28	1.5455 28	1.5452 12	1.5814 28	1.5444 26	1.5419 10	1.6051 4	1.5506 17	1.5655 4
hartree fock	ROHF	1.6134 2	1.5952 2	1.5167 2	1.6419 2	1.5076 3	1.5064 2	1.5072 2	1.4972 2	1.4972 2	1.4816 2			1.5234 2	1.4812 2	1.4756 2	1.5233 2	1.4823 2	1.4756 2
density functional	LSDA	1.7184 28	1.6461 28	1.5960 28	1.7384 28	1.6023 28	1.6023 28	1.6142 28	1.6117 28	1.6117 28	1.5778 28		1.5925 2	1.6237 28	1.5927 28	1.5659 4	1.6288 28	1.5723 10	1.5646 4	1.6523 4	1.6271 4	1.6326 4
	SVWN		1.6857 25			1.6042 23	1.5769 2	1.6160 25	1.5825 2	1.5825 2	1.5442 2			1.6047 2	1.5616 2		1.6086 2	1.5638 2		1.6523 4	1.6271 4	1.6326 4
	BLYP	1.7593 26	1.7285 28	1.6381 28	1.7836 28	1.6445 28	1.6445 28	1.6614 28	1.6592 28	1.6592 28	1.6199 28		1.6437 2	1.6666 28	1.6365 28		1.6587 8			1.7022 4	1.6795 4	1.6880 4
	B1B95	1.7094 26	1.6286 26	1.5906 26	1.7296 26	1.5957 28	1.5960 26	1.6044 26	1.6016 26	1.6016 26	1.5737 26		1.5766 2	1.6166 26	1.5813 26	1.5479 5	1.6227 24	1.5808 14	1.5469 5	1.6445 4	1.6100 5	1.6170 4
	B3LYP	1.7234 26	1.6910 28	1.6085 28	1.7462 28	1.6138 28	1.6138 28	1.6252 28	1.6218 28	1.6272 20	1.5894 28	1.5814 8	1.6621 32	1.6345 28	1.6020 28	1.6008 10	1.6388 27	1.6043 17	1.6011 10	1.6642 4	1.6052 17	1.6414 4
	B3LYPultrafine					1.6106 24		1.6302 3
	B3PW91	1.7158 18	1.6851 28	1.6026 28	1.7397 28	1.6068 28	1.6068 28	1.6156 28	1.6131 28	1.6182 20	1.5837 28		1.5895 2	1.6269 28	1.5936 28		1.6154 8			1.6558 4	1.6262 4	1.6299 4
	mPW1PW91	1.7076 18	1.6769 28	1.5959 26	1.7318 26	1.6003 28	1.6003 28	1.6087 28	1.6054 28	1.6054 28	1.5775 28		1.5812 2	1.6203 28	1.5873 27		1.6096 13	1.5755 5		1.6478 4	1.6174 4	1.6209 4
	M06-2X	1.7088 2	1.6415 2	1.5575 2	1.7033 2	1.5908 25	1.5626 2	1.5686 2	1.5637 2	1.5637 2	1.5355 2		1.5697 2	1.5860 2	1.5449 2		1.5851 2	1.5459 2		1.6362 4	1.6100 4	1.6127 4
	PBEPBE	1.7442 18	1.7147 28	1.6317 20	1.7730 20	1.6306 28	1.6305 28	1.6442 28	1.6421 28	1.6420 28	1.6080 28	1.6120 12	1.6243 2	1.6521 28	1.6210 28	1.5802 5	1.6382 6	1.6101 15	1.5792 5	1.6852 4	1.6593 4	1.6661 4
	PBEPBEultrafine					1.6312 14
	HSEh1PBE	1.7499 2	1.6660 2	1.5659 2	1.7348 2	1.6038 24	1.5735 2	1.5813 2	1.5751 2	1.5751 2	1.5430 2		1.5832 2	1.5991 2	1.5541 2		1.5999 2	1.5558 2		1.6496 4	1.6194 4	1.6231 4
Moller Plesset perturbation	MP2FC	1.6909 18	1.6781 28	1.6009 28	1.7496 28	1.6101 28	1.6101 28	1.6224 28	1.6065 28	1.6065 28	1.5815 27		1.6454 32	1.6283 28	1.5871 27	1.6106 3	1.6370 24	1.5739 10	1.6105 3	1.6625 4	1.5909 17	1.6292 4
	MP2FU	1.6907 18	1.6777 27	1.5998 26	1.7470 26	1.6073 28	1.6073 28	1.6195 28	1.6060 28	1.6105 18	1.5779 18		1.5882 2	1.6272 27	1.5848 27	1.6085 3	1.6496 10	1.5427 6	1.6114 2	1.6618 4	1.5886 17	1.6246 4
	ROMP2	1.6286 2	1.6286 2	1.5441 2	1.6808 2	1.5415 2	1.5415 2	1.5474 2	1.5296 2	1.5296 2	1.5141 2			1.5568 2	1.5153 2	1.5087 2	1.5648 2	1.5189 2	1.5093 2
	MP3					1.6004 28														1.6478 4	1.6005 4	1.6042 4
	MP4	1.7643 4	1.6871 26			1.6222 21			1.6397 1	1.6210 18	1.6074 4				1.5858 9					1.6713 4	1.6285 4	1.6392 4
	B2PLYP	1.7686 2	1.6788 2	1.5738 2	1.7612 2	1.6103 25	1.5834 2	1.6233 25	1.5843 2	1.5843 2	1.5494 2		1.5945 2	1.6100 2	1.5609 2		1.6140 2	1.5637 2		1.6629 4	1.6300 4	1.6366 4
Configuration interaction	CID	1.7378 4	1.6634 20	1.5845 26	1.7146 26	1.5869 28			1.5793 27	1.5996 4	1.5748 4
Configuration interaction	CISD	1.7384 4	1.6670 20	1.5930 20	1.7231 20	1.5882 28			1.5794 26	1.6006 4	1.5754 4
Quadratic configuration interaction	QCISD	1.7586 4	1.6825 28	1.6018 26	1.7526 26	1.6085 27	1.6074 26	1.6241 21	1.6033 27	1.5918 22	1.5752 12		1.5758 2	1.6264 27	1.5770 14		1.6006 2			1.6557 4	1.6081 4	1.6134 4
Quadratic configuration interaction	QCISD(T)					1.6189 21			1.6395 1				1.5872 2	1.6117 7	1.5616 7		1.6150 7	1.5645 7
Coupled Cluster	CCD	1.7561 4	1.6702 26	1.5949 26	1.7346 26	1.6018 28	1.6014 26	1.6142 20	1.5959 27	1.5861 14	1.5630 14		1.5690 2	1.6191 27	1.5678 13		1.5965 7	1.5470 7		1.6478 4	1.5995 5	1.6053 4
	CCSD					1.6105 21			1.6301 1					1.5957 2	1.5393 2
	CCSD(T)					1.6177 22	1.6370 1		1.6377 1			1.6123 1	1.5855 2	1.6392 14	1.5894 14	1.5125 1	1.6448 14	1.5767 10	1.5131 1		1.6041 1
	CCSD(T)=FULL					1.6190 5							1.5846 2	1.6220 3	1.5677 3	1.5108 1	1.6248 3	1.6110 1	1.5103 1	1.6639 4	1.6134 5	1.6356 2

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	1.7193 25	1.5733 28	1.7119 27	1.5734 28	1.6902 28	1.6825 28
density functional	B1B95	1.7658 14	1.6170 14
density functional	B3LYP	1.7812 28	1.6288 28	1.7774 28	1.6297 28	1.7602 27	1.7540 27
Moller Plesset perturbation	MP2FC	1.7982 28	1.6288 28	1.7907 28	1.6284 28	1.7723 28	1.7679 28

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.