III.G.1.a.

Comparison of levels of theory for C-P

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	1.4437 3
	PM3	1.5083 7
	PM6	1.6015 7
composite	G2	1.6274 6
	G3	1.6257 7
	G3B3	1.6370 7
	CBS-Q	1.6263 7

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	1.6475 6	1.6747 7	1.6259 6	1.6760 7	1.6258 7	1.6256 7	1.6264 7	1.6219 7	1.6219 7	1.6155 6	1.6498 4	1.6278 7	1.6326 7	1.6218 7	1.6159 6	1.6349 7	1.6223 7	1.6161 6	1.5849 3
hartree fock	ROHF		1.5661 1	1.5249 1		1.5522 2	1.5241 1	1.5252 1	1.5216 1					1.5330 1	1.5221 1
density functional	LSDA	1.6552 7	1.6550 7	1.6329 7	1.6757 7	1.6347 7	1.6346 7	1.6342 7	1.6279 7	1.6281 7	1.6268 7			1.6407 7	1.6258 7	1.5961 1	1.6405 7	1.5916 3	1.5944 1
	SVWN		1.6736 7			1.6478 6		1.6341 7
	BLYP	1.6658 6	1.6964 7	1.6533 7	1.6992 7	1.6558 7	1.6556 7	1.6556 7	1.6502 7	1.6502 7	1.6416 6			1.6608 7	1.6471 7		1.6854 3
	B1B95	1.6203 7	1.6509 7	1.6286 7	1.6726 7	1.6288 7	1.6298 7	1.6294 7	1.6255 7	1.6256 7	1.6238 7			1.6360 7	1.6230 7	1.5679 2	1.6356 7	1.5880 3	1.5675 2
	B3LYP	1.6449 7	1.6785 7	1.6352 7	1.6808 7	1.6371 7	1.6369 7	1.6371 7	1.6321 7	1.5947 3	1.6236 6	1.7075 2	1.6356 7	1.6428 7	1.6298 7	1.6323 5	1.6435 7	1.6298 7	1.6323 5	1.5829 3
	B3LYPultrafine					1.6370 7		1.8768 1
	B3PW91	1.6113 4	1.6878 6	1.6326 7	1.6888 6	1.6334 7	1.6332 7	1.6330 7	1.6283 7	1.5916 3	1.6207 6			1.6393 7	1.6268 7		1.6635 3
	mPW1PW91	1.6197 5	1.6721 7	1.6117 4	1.6732 7	1.6297 7	1.6296 7	1.6294 7	1.6249 7	1.6252 7	1.6173 6			1.6355 7	1.6236 7		1.6602 3
	M06-2X					1.6249 7
	PBEPBE	1.6283 4	1.6904 7	1.6320 4	1.6780 4	1.6491 7	1.6489 7	1.6486 7	1.6438 7	1.6439 7	1.6362 6	1.6627 4		1.6545 7	1.6418 7	1.5856 2	1.5766 1	1.6470 5	1.5849 2	1.5668 1
	PBEPBEultrafine					1.6747 4
	HSEh1PBE					1.6443 6
Moller Plesset perturbation	MP2FC	1.6785 4	1.7042 7	1.6444 7	1.7076 7	1.6388 7	1.6385 7	1.6383 7	1.6338 7	1.6340 7	1.6069 5		1.6405 7	1.6521 7	1.6268 6	1.5533 2	1.6548 7	1.6334 7	1.5069 1	1.5785 3
	MP2FU	1.6783 4	1.7044 7	1.6346 4	1.6992 4	1.6369 7	1.6365 7	1.6364 7	1.6326 7	1.6079 3	1.6017 3			1.6507 7	1.6191 4	1.5482 2	1.5828 3	1.6003 1		1.5724 3
	MP3					1.6261 7
	MP4	1.6790 1	1.7004 3			1.6612 6			1.6609 4	1.6212 3					1.6039 5
	B2PLYP					1.6373 7		1.6373 7
Configuration interaction	CID		1.6570 3	1.5947 3	1.6611 3	1.6261 7			1.6218 7
Configuration interaction	CISD		1.6369 4	1.5974 3	1.6369 2	1.6293 7	1.5379 1		1.5892 3
Quadratic configuration interaction	QCISD	1.6831 1	1.6999 7	1.6279 4	1.6751 4	1.6410 7	1.6241 4	1.6405 7	1.6374 7	1.6309 6	1.5995 3			1.6542 7	1.6076 5					1.5601 1
Quadratic configuration interaction	QCISD(T)					1.6643 5			1.6697 4					1.6313 3	1.6117 3		1.6201 2	1.5988 2
Coupled Cluster	CCD	1.6827 1	1.6809 4	1.6217 4	1.6858 4	1.6321 7	1.6171 4	1.6168 4	1.6276 7	1.5945 3	1.5916 3			1.6604 6	1.6113 4		1.6168 3	1.5926 3
	CCSD					1.6553 5			1.6624 4
	CCSD(T)		1.6285 1			1.6727 4	1.6717 4	1.5756 1	1.6690 4	1.5712 1		1.5624 1		1.6305 3	1.6005 4	1.5699 1	1.6327 3	1.6107 3		1.5653 1
	CCSD(T)=FULL					1.6287 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	1.6869 7	1.6471 7	1.6847 7	1.6407 7	1.6949 5	1.6681 7
density functional	B1B95	1.7128 4	1.7140 3
density functional	B3LYP	1.6974 7	1.6578 7	1.6950 7	1.6538 7	1.7159 5	1.6737 7
Moller Plesset perturbation	MP2FC	1.7275 7	1.6676 7	1.7188 7	1.6568 7	1.7883 5	1.7022 7

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.