III.G.1.a.

Comparison of levels of theory for O-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	1.4461 8
	PM3	1.4542 13
	PM6	1.4985 16
composite	G2	1.4978 18
	G3	1.4912 20
	G3B3	1.5249 21
	CBS-Q	1.4976 17

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	cc-pCVTZ
hartree fock	HF	1.6108 20	1.5701 21	1.4998 21	1.6041 21	1.4961 19	1.4926 21	1.4940 21	1.4855 21	1.4856 21	1.4794 21	1.4283 6	1.4982 21	1.5102 21	1.4847 21	1.4435 11	1.5131 21	1.4733 17	1.4457 9	1.4782 10
hartree fock	ROHF	1.5420 5	1.5387 6	1.4575 6	1.5638 5	1.4469 6	1.4469 6	1.4474 6	1.4380 6	1.4361 5	1.4333 5			1.4629 6	1.4396 6	1.4355 3	1.4651 5	1.4389 5	1.4355 3
density functional	LSDA	1.6277 21	1.5683 21	1.5263 21	1.6242 21	1.5255 21	1.5253 21	1.5271 21	1.5182 21	1.5184 21	1.5081 21		1.5763 4	1.5448 21	1.5158 21	1.4636 5	1.5460 21	1.4691 5	1.4616 5
	SVWN		1.5942 19			1.5257 19	1.5699 4	1.5269 19	1.5638 4	1.5646 4	1.5527 4			1.5904 4	1.5612 4		1.5910 4
	BLYP	1.6622 20	1.6205 21	1.5501 21	1.6540 21	1.5486 21	1.5484 21	1.5509 21	1.5419 21	1.5421 21	1.5304 21		1.6066 4	1.5685 21	1.5386 21		1.5255 6
	B1B95	1.5986 17	1.5323 17	1.5054 17	1.6036 17	1.5004 17	1.5013 17	1.5015 17	1.4937 17	1.4939 17	1.4870 17		1.5712 4	1.5186 17	1.4917 17	1.4547 5	1.5192 17	1.4741 7	1.4531 5
	B3LYP	1.6353 21	1.5975 21	1.5288 21	1.6294 21	1.5268 21	1.5265 21	1.5287 21	1.5200 21	1.5345 16	1.5102 21	1.4651 6	1.5335 21	1.5457 21	1.5175 21	1.4768 9	1.5546 19	1.5129 15	1.4759 9	1.5119 10
	B3LYPultrafine					1.5268 21		1.4961 3
	B3PW91	1.6459 16	1.5951 21	1.5263 21	1.6257 21	1.5237 21	1.5234 21	1.5248 21	1.5166 21	1.5309 16	1.5082 21		1.5791 4	1.5424 21	1.5146 21		1.5013 6
	mPW1PW91	1.6311 17	1.5905 21	1.5298 18	1.6210 21	1.5193 21	1.5191 21	1.5205 21	1.5122 21	1.5124 21	1.5042 21		1.5747 4	1.5379 21	1.5168 19		1.5339 10
	M06-2X	1.6668 4	1.6164 4	1.5573 4	1.6537 4	1.5144 19	1.5651 4	1.5659 4	1.5596 4	1.5602 4	1.5513 4		1.5697 4	1.5835 4	1.5568 4		1.5840 4
	PBEPBE	1.6683 16	1.6154 21	1.5603 15	1.6623 15	1.5432 21	1.5430 21	1.5446 21	1.5361 21	1.5363 21	1.5268 21	1.4809 6	1.5992 4	1.5629 21	1.5337 21	1.4788 5	1.6143 4	1.5024 4	1.4768 5	1.4955 1
	PBEPBEultrafine					1.5010 6
	HSEh1PBE	1.6868 4	1.6277 4	1.5638 4	1.6672 4	1.5208 19	1.5699 4	1.5709 4	1.5639 4	1.5646 4	1.5548 4		1.5760 4	1.5898 4	1.5617 4		1.5903 4
Moller Plesset perturbation	MP2FC	1.6423 16	1.6048 21	1.5298 21	1.6444 21	1.5333 20	1.5331 20	1.5384 20	1.5170 21	1.5215 20	1.5145 20		1.5285 21	1.5478 21	1.5256 19	1.4970 3	1.5634 19	1.4912 6	1.4965 3	1.5149 10	1.4909 1
	MP2FU	1.6453 15	1.6118 19	1.5411 17	1.6529 17	1.5319 20	1.5316 20	1.5368 20	1.5188 20	1.5365 15	1.5247 15		1.5792 4	1.5509 19	1.5251 17	1.4936 3	1.5612 10	1.4693 3	1.4939 2	1.5110 10	1.4890 1
	ROMP2	1.5682 3	1.5759 3	1.4941 3	1.5566 2	1.4673 2	1.4673 2	1.4698 2	1.4634 3	1.4654 3	1.4532 2			1.4980 3	1.4591 2	1.4522 2	1.4871 2	1.4613 2	1.4527 2
	MP3					1.5162 21
	MP4		1.6587 15			1.5508 17			1.4915 2	1.5362 11					1.5349 17
	B2PLYP	1.6883 4	1.6325 4	1.5680 4	1.6777 4	1.5289 19	1.5750 4	1.5317 19	1.5675 4	1.5685 4	1.5585 4		1.5812 4	1.5949 4	1.5656 4		1.5976 4
Configuration interaction	CID		1.5913 17	1.5232 17	1.6329 15	1.5099 21			1.5042 19
Configuration interaction	CISD		1.5949 17	1.5254 17	1.6362 15	1.5109 21			1.5090 17
Quadratic configuration interaction	QCISD		1.6073 21	1.5388 17	1.6587 17	1.5333 19	1.5365 17	1.5380 18	1.5202 19	1.5189 17	1.5270 13		1.5756 4	1.5353 15	1.5035 11		1.5971 4			1.4796 1
Quadratic configuration interaction	QCISD(T)					1.5389 19			1.5002 2				1.5811 4	1.5483 9	1.4771 5		1.5139 5	1.4791 4
Coupled Cluster	CCD		1.5998 17	1.5306 17	1.6388 17	1.5197 21	1.5309 17	1.5344 17	1.5115 19	1.5289 13	1.5183 13		1.5716 4	1.5285 14	1.4982 9		1.5414 9	1.4589 4
	CCSD					1.5234 21			1.4753 2					1.5910 4	1.5577 4
	CCSD(T)		1.6028 1			1.5270 12	1.5071 2	1.4913 1	1.4881 2	1.4757 1		1.4847 1	1.5803 4	1.5472 11	1.5087 14		1.5258 7	1.4908 6		1.4867 1	1.4872 1
	CCSD(T)=FULL					1.5480 7							1.5791 4	1.5948 4	1.4917 1		1.5994 4				1.4850 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	1.6081 21	1.5093 21	1.6064 21	1.5084 21	1.5949 21	1.5878 21
density functional	B1B95	1.5917 6	1.4948 6
density functional	B3LYP	1.6386 21	1.5450 20	1.6375 20	1.5452 20	1.6237 21	1.6174 20
Moller Plesset perturbation	MP2FC	1.6517 21	1.5475 21	1.6528 20	1.5497 21	1.6316 21	1.6226 21

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.