III.G.1.a.

Comparison of levels of theory for S-N

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	1.4397 3
	PM3	1.4989 4
	PM6	1.5268 6
composite	G2	1.5729 6
	G3	1.5728 6
	G3B3	1.5851 6
	CBS-Q	1.5722 6

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
hartree fock	HF	1.6140 5	1.7063 6	1.5980 6	1.6984 6	1.6081 5	1.5726 6	1.5649 6	1.5702 6	1.5702 6	1.5551 6	1.5192 1	1.5133 5	1.5810 6	1.5557 6	1.5460 6	1.5728 6	1.5503 6	1.5428 6	1.5239 1
hartree fock	ROHF	1.6753 1	1.7349 3	1.6452 3	1.8063 2	1.6249 4	1.6147 3	1.6070 3	1.6145 3	1.6838 2	1.6383 1			1.6237 3	1.5975 3	1.6739 1	1.6804 2	1.6546 2	1.6685 1
density functional	LSDA	1.6454 6	1.6122 6	1.5991 6	1.6795 6	1.5793 6	1.5793 6	1.5674 6	1.5733 6	1.5735 6	1.5624 6			1.5878 6	1.5612 6	1.5005 2	1.5741 6	1.5583 4	1.4330 1
	SVWN		1.6366 5			1.5326 5		1.5226 5
	BLYP	1.6833 5	1.7180 6	1.6342 6	1.7317 5	1.6114 6	1.6114 6	1.5982 6	1.6230 5	1.6079 6	1.5935 6			1.6193 6	1.6066 5		1.5393 1
	B1B95	1.6317 6	1.6065 6	1.5935 6	1.6705 6	1.5719 6	1.5723 6	1.5619 6	1.5688 6	1.5690 6	1.5579 6			1.5805 6	1.5571 6	1.5262 3	1.5689 6	1.5609 5	1.5181 3	1.4864 1
	B3LYP	1.6440 6	1.6900 6	1.6070 6	1.6858 6	1.5861 6	1.5860 6	1.5753 6	1.5822 6	1.5971 5	1.5699 6	1.4903 1	1.5826 6	1.5940 6	1.5690 6	1.5593 6	1.5816 6	1.5603 6	1.5533 6	1.4926 1
	B3LYPultrafine					1.5862 6
	B3PW91	1.6502 5	1.6992 5	1.6002 6	1.6778 6	1.5790 6	1.5789 6	1.5685 6	1.5750 6	1.5893 5	1.5638 6			1.5870 6	1.5629 6		1.5144 1
	mPW1PW91	1.6239 6	1.6495 5	1.6101 5	1.6723 6	1.5742 6	1.5741 6	1.5640 6	1.5705 6	1.5707 6	1.5593 6			1.5820 6	1.5586 6		1.5949 3	1.6172 2
	M06-2X	1.7139 1	1.8049 1	1.7266 1	1.7987 1	1.5685 5	1.6962 1	1.6835 1	1.6983 1	1.6989 1	1.6791 1			1.7038 1	1.6788 1		1.6905 1	1.6693 1
	PBEPBE	1.6715 5	1.7054 6	1.6370 5	1.7171 5	1.5987 6	1.5986 6	1.5862 6	1.5951 6	1.5953 6	1.5828 6	1.5049 1		1.6067 6	1.5817 6	1.5479 3	1.6617 2	1.5991 3	1.5370 3
	PBEPBEultrafine					1.5291 1
	HSEh1PBE	1.7271 1	1.8191 1	1.7326 1	1.8135 1	1.5755 5	1.7045 1	1.6899 1	1.7056 1	1.7057 1	1.6870 1			1.7109 1	1.6860 1		1.6969 1	1.6745 1
Moller Plesset perturbation	MP2FC	1.6780 4	1.7139 6	1.5972 6	1.7112 6	1.5666 6	1.5662 6	1.5559 6	1.5605 6	1.5607 6	1.5771 5		1.5651 6	1.5798 6	1.5511 6	1.5210 4	1.5727 6	1.5441 6	1.5163 4	1.4154 1
	MP2FU	1.6778 4	1.7140 6	1.6249 5	1.7274 5	1.5648 6	1.5645 6	1.5789 5	1.5858 5	1.5860 5	1.5721 5			1.5932 6	1.5470 6	1.5300 5	1.5854 4	1.5522 4	1.5548 4	1.4115 1
	ROMP2	1.7027 1	1.6863 2	1.6863 2	1.7854 2	1.6323 2	1.6316 2	1.6043 2	1.6303 2	1.6301 2	1.6056 2			1.6431 2	1.5977 2		1.6128 2
	MP3					1.5634 6
	MP4		1.8248 5			1.5870 6			1.4530 1	1.6070 5					1.5651 5
	B2PLYP	1.7344 1	1.8332 1	1.7438 1	1.8287 1	1.5370 5	1.7114 1	1.5292 5	1.7119 1	1.7118 1	1.6962 1			1.7214 1	1.6961 1		1.7106 1	1.6909 1
Configuration interaction	CID		1.7035 5	1.6104 5	1.6973 5	1.5638 6			1.5576 6
Configuration interaction	CISD		1.7161 5	1.6169 5	1.7104 5	1.5712 6			1.5811 5
Quadratic configuration interaction	QCISD		1.7304 6	1.6358 5	1.7491 5	1.5922 6	1.6061 5	1.5957 5	1.5853 6	1.5999 5	1.5885 5			1.6193 5	1.5739 6		1.6645 2	1.6333 2
Quadratic configuration interaction	QCISD(T)					1.6121 5			1.5274 1					1.6259 5	1.5956 5		1.5825 3	1.5524 3
Coupled Cluster	CCD		1.7111 5	1.6168 5	1.7053 5	1.5678 6	1.5875 5	1.5766 5	1.5614 6	1.5822 5	1.5714 5			1.5998 5	1.5702 5		1.5919 5	1.5629 5		1.4422 1
	CCSD					1.5862 6			1.5082 1					1.6626 2	1.6345 2
	CCSD(T)					1.6155 3	1.5235 1		1.5147 1			1.4966 1		1.6236 5	1.5793 6	1.6223 3	1.6168 5	1.5865 5	1.6302 2	1.5008 1
	CCSD(T)=FULL					1.5852 5								1.6267 3	1.6008 4	1.5971 1	1.6248 3	1.5917 3		1.5004 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	1.6993 6	1.5814 6	1.6981 6	1.5797 6	1.6771 5	1.6782 6
density functional	B1B95	1.6127 1	1.5201 1
density functional	B3LYP	1.6973 6	1.5970 6	1.6917 6	1.5947 6	1.7008 5	1.6709 6
Moller Plesset perturbation	MP2FC	1.7196 6	1.5810 6	1.7116 6	1.5765 6	1.7195 5	1.6881 6

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.