III.G.1.a.

Comparison of levels of theory for Cl-O

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	1.6400 6
	PM3	1.5636 17
	PM6	1.5833 40
composite	G2	1.5757 31
	G3	1.5531 32
	G3B3	1.6185 32
	CBS-Q	1.5486 31
molecular mechanics	DREIDING	1.6465 1

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	cc-pCVDZ	cc-pCVTZ
hartree fock	HF	1.9152 28	1.9011 30	1.5695 31	2.0197 25	1.5498 40	1.5502 32	1.5569 34	1.6085 32	1.5430 31	1.5242 32	1.5247 11	1.5553 40	1.6253 32	1.5346 34	1.5462 14	1.5534 30	1.5138 30	1.5349 9	1.6688 1	1.4768 18	1.6543 2	1.5853 1
hartree fock	ROHF	1.7232 3	1.7099 8	1.5719 8	1.7165 4	1.5440 9	1.5498 8	1.5492 8	1.5483 8	1.5371 4	1.4762 3			1.5636 8	1.5293 8	1.5149 4	1.5530 4	1.5219 4	1.5148 4
density functional	LSDA	1.8285 29	1.7099 32	1.6197 32	1.7788 29	1.6020 32	1.6018 32	1.6047 32	1.6081 32	1.6072 32	1.5723 32		1.6993 7	1.6158 32	1.5799 32	1.5321 4	1.6134 31	1.5753 11	1.5320 4	1.6959 1		1.7084 1	1.6777 1
	SVWN		1.7286 35			1.5916 33	1.6840 7	1.5894 35	1.6970 7	1.6927 7	1.6509 7			1.6977 7	1.6616 7		1.7076 6	1.5495 3
	BLYP	1.8874 29	1.8169 32	1.6819 29	1.8403 32	1.6575 32	1.6573 32	1.6631 32	1.6705 29	1.6669 32	1.6263 32		1.7757 7	1.6729 32	1.6372 29		1.6779 11			1.7596 1		1.7710 1	1.7396 1
	B1B95	1.8223 22	1.6995 25	1.6393 25	1.8080 22	1.6024 24	1.6309 25	1.6427 22	1.6374 25	1.6365 25	1.5786 24		1.6796 7	1.6534 22	1.6094 25	1.4961 5	1.6386 24	1.5475 10	1.4960 5	1.6980 1	1.5631 1	1.7083 1	1.6775 1
	B3LYP	1.8531 29	1.7843 31	1.6363 29	1.8081 29	1.6345 34	1.6233 32	1.6373 34	1.6304 32	1.6102 21	1.5933 32	1.6205 11	1.6313 40	1.6375 32	1.6107 34	1.5854 9	1.6515 28	1.6073 27	1.5849 9	1.7228 1	1.5525 18	1.6809 2	1.6419 2
	B3LYPultrafine					1.6235 32		1.7562 7
	B3PW91	1.8594 22	1.7602 32	1.6228 29	1.7931 29	1.6140 29	1.6138 29	1.6109 32	1.6149 32	1.5954 21	1.5780 32		1.6952 7	1.6227 32	1.5893 29		1.6412 11			1.7070 1		1.7180 1	1.6868 1
	mPW1PW91	1.8541 21	1.7558 32	1.6064 22	1.7888 29	1.6096 29	1.6092 29	1.6114 29	1.6082 32	1.6076 32	1.5817 29		1.6833 7	1.6168 32	1.5825 32		1.6662 18	1.5727 4		1.6995 1		1.7103 1	1.6796 1
	M06-2X	1.7623 1	1.8824 4	1.7759 4	1.9047 4	1.5869 35	1.6570 7	1.7507 4	1.6632 7	1.6594 7	1.6325 7		1.6647 7	1.7549 4	1.7268 4		1.6705 6	1.5222 3		1.6925 1	1.6735 1	1.7016 1	1.6737 1
	PBEPBE	1.8859 19	1.8078 26	1.6566 19	1.8244 19	1.6362 29	1.6360 29	1.6368 32	1.6411 32	1.6403 32	1.6045 32	1.6094 11	1.7401 7	1.6473 32	1.6108 32	1.5474 5	1.7229 9	1.6540 13	1.5471 5	1.7317 1	1.6480 2	1.7431 1	1.7119 1
	PBEPBEultrafine					1.6469 11		1.7369 1
	HSEh1PBE	1.9877 4	1.8422 7	1.7903 4	1.9481 4	1.5933 31	1.7627 4	1.7698 4	1.6817 7	1.6780 7	1.6443 7		1.6841 7	1.7740 4	1.6515 7		1.6904 6	1.5351 3		1.7002 1	1.6795 1	1.7109 1	1.6801 1
Moller Plesset perturbation	MP2FC	1.8983 19	1.7519 33	1.6182 31	1.7739 29	1.6004 34	1.5911 32	1.6046 34	1.5927 29	1.5888 32	1.5631 26		1.5941 40	1.6056 32	1.5750 34	1.5559 1	1.6256 28	1.5896 14	1.5540 1	1.7180 1	1.5099 18	1.6725 2	1.6240 2
	MP2FU	1.9044 18	1.7605 28	1.6106 20	1.7911 18	1.5983 34	1.5890 32	1.6053 31	1.5888 32	1.5848 21	1.5517 21		1.6969 7	1.6207 29	1.5716 24	1.5523 1	1.7029 13	1.5698 9		1.7169 1	1.5068 18	1.6713 2	1.6211 2
	ROMP2	1.7828 3	1.8281 1	1.5224 2	1.7377 3	1.5412 3	1.5412 3	1.5426 3	1.5471 3	1.5471 3	1.5133 3			1.5750 3	1.5173 3	1.4405 2	1.5737 3	1.5185 3	1.5059 3
	MP3					1.5817 32															1.6857 1
	MP4		1.7236 14			1.6421 28			1.6992 3	1.6120 20					1.6577 18					1.7344 1	1.7037 1	1.7436 1	1.7035 1
	B2PLYP	1.7921 1	1.8970 7	1.7256 7	1.9465 7	1.5929 35	1.7902 4	1.5974 32	1.7113 7	1.7075 7	1.6649 7		1.7161 7	1.7163 7	1.6734 7		1.7292 6			1.7204 1	1.6973 1	1.7307 1	1.6976 1
Configuration interaction	CID		1.7515 21	1.5863 21	1.7808 18	1.5690 32			1.5719 24
Configuration interaction	CISD		1.7684 21	1.5923 21	1.7961 20	1.5772 29	1.7054 1		1.5614 21
Quadratic configuration interaction	QCISD		1.7790 19	1.6254 20	1.8153 12	1.6237 29	1.5987 21	1.6165 28	1.6109 28	1.5883 30	1.5649 21		1.6883 7	1.6660 21	1.6231 18		1.7103 7	1.6979 1		1.7242 1	1.6365 2	1.7333 1	1.6892 1
Quadratic configuration interaction	QCISD(T)					1.6144 32		1.5287 4	1.6871 2	1.5141 4			1.7139 7	1.6869 14	1.6221 13		1.6786 12	1.5232 5		1.7374 1	1.6894 1	1.7467 1	1.7021 1
Coupled Cluster	CCD		1.7590 21	1.6001 21	1.7853 21	1.5839 32	1.5782 21	1.5812 21	1.5883 24	1.5730 21	1.5464 21		1.6683 7	1.6470 22	1.5919 14		1.6311 13	1.5185 9		1.7176 1	1.6306 2	1.7264 1	1.6843 1
	CCSD					1.6014 32			1.6748 2					1.6975 8	1.6494 8
	CCSD(T)		1.8453 2			1.5967 34	1.7170 5	1.6257 8	1.7023 3	1.5696 6		1.5777 1	1.7077 7	1.7020 12	1.6444 19	1.5984 2	1.6764 14	1.5581 7	1.4959 1	1.7371 1	1.6431 2	1.6956 2	1.6430 2
	CCSD(T)=FULL					1.6852 11							1.7058 7	1.7143 9	1.6928 4	1.4925 1	1.7291 7	1.7073 1	1.4923 1	1.7357 1	1.6389 2	1.6940 2	1.6397 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	1.9044 27	1.5632 31	2.1037 28	1.5611 31	1.9511 27	2.0758 28
density functional	B1B95	1.8329 11	1.6559 11	1.8179 1	1.7123 1	1.8199 1	1.8186 1
density functional	B3LYP	1.8300 29	1.6472 28	1.8230 29	1.6400 31	1.7706 24	1.7910 26
Moller Plesset perturbation	MP2FC	1.7671 23	1.6106 31	1.7439 26	1.6073 31	1.7663 22	1.7430 26

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.