III.G.1.a.

Comparison of levels of theory for C-Br

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	1.9583 2
	PM3	1.9003 7
	PM6	1.9287 28
composite	G2	1.9075 28
	G3	1.8980 13
	G3B3	1.9316 13
	CBS-Q	1.8910 16

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
hartree fock	HF	1.9007 17	1.9549 28	1.9079 28	1.9407 28	1.9075 28	1.9072 28	1.9028 28	1.9093 28	1.9072 27	1.8850 26	1.9176 13	1.8987 33	1.9116 28	1.9065 28	1.8894 16	1.9100 28	1.9092 25	1.8889 12	1.7145 1	1.7094 1
hartree fock	ROHF		1.9367 9	1.8786 9	1.9164 9	1.8787 9	1.8784 9	1.8746 9	1.8811 9	1.8809 9				1.8833 9	1.8777 9	1.8760 9	1.8814 9	1.8776 9	1.8758 9		1.7094 1
density functional	LSDA	1.9183 28	1.9122 28	1.8934 28	1.9326 28	1.8979 28	1.8975 28	1.8914 28	1.9018 28	1.9018 28	1.8704 28			1.9035 28	1.8942 28		1.9004 28	1.8779 12			1.6685 1
	SVWN		1.9423 15			1.9057 15		1.8996 15
	BLYP	1.9581 18	1.9927 29	1.9490 29	1.9944 29	1.9579 29	1.9576 29	1.9503 29	1.9631 29	1.9612 28	1.9269 27			1.9633 29	1.9558 29		1.9688 11				1.7126 1
	B1B95	1.9215 27	1.9202 27	1.9020 27	1.9386 27	1.9030 27	1.9039 27	1.8999 28	1.9081 27	1.9080 27	1.8801 26			1.9089 27	1.9014 27		1.9049 27	1.8899 13			1.6822 1
	B3LYP	1.9389 28	1.9680 26	1.9248 28	1.9656 28	1.9303 28	1.9299 28	1.9239 28	1.9342 28	1.9323 27	1.9022 26		1.9211 33	1.9349 28	1.9279 28	1.9097 12	1.9321 28	1.9202 23	1.9092 12	1.7055 1	1.6984 1
	B3LYPultrafine					1.9230 14
	B3PW91	1.9262 18	1.9565 29	1.9128 29	1.9506 29	1.9169 28	1.9160 29	1.9096 29	1.9198 29	1.9180 28	1.8895 27			1.9207 29	1.9139 29		1.9275 11				1.6898 1
	mPW1PW91	1.9143 28	1.9505 28	1.9071 28	1.9437 28	1.9099 27	1.9090 28	1.9033 28	1.9129 28	1.9110 27	1.8833 26			1.9136 28	1.9072 28		1.9095 24	1.8910 12			1.6870 1
	M06-2X	1.9551 3	1.9697 3	1.9287 3	1.9515 3	1.9198 18	1.9343 3	1.9260 3	1.9386 3	1.9386 3	1.9086 3			1.9404 3	1.9358 3		1.9347 3	1.9312 2			1.6920 1
	PBEPBE	1.9360 17	1.9695 28	1.9257 28	1.9671 28	1.9307 27	1.9296 28	1.9230 28	1.9349 28	1.9331 27	1.9010 26	1.9498 6		1.9348 28	1.9279 28		1.9298 24	1.9188 21		1.7015 1	1.6959 1
	PBEPBEultrafine					1.9379 13
	HSEh1PBE	1.9671 3	1.9718 3	1.9281 3	1.9614 3	1.9219 18	1.9408 3	1.9317 3	1.9446 3	1.9446 3	1.9117 3			1.9456 3	1.9402 3		1.9392 3	1.9360 2			1.6864 1
Moller Plesset perturbation	MP2FC	1.9268 17	1.9793 28	1.9256 28	1.9694 28	1.9199 28	1.9187 28	1.9127 28	1.9139 28	1.9113 27	1.8829 26		1.8998 33	1.9178 28	1.8869 18	1.6877 2	1.9144 28	1.8833 13	1.6877 1	1.7005 1	1.6884 1
	MP2FU	1.9267 17	1.9788 28	1.9248 28	1.9677 28	1.9154 28	1.9142 28	1.9082 28	1.9104 28	1.9077 27	1.8647 26			1.9158 28	1.8810 19	1.6835 2	1.8938 15	1.8705 12	1.6827 1	1.6981 1	1.6829 1
	ROMP2	1.7771 2	1.7198 2	1.7198 2	1.7982 2	1.6998 2	1.6976 2	1.6972 2	1.7002 2	1.6986 2	1.6960 2			1.7077 2	1.6928 2		1.7128 2
	MP3					1.9272 27
	MP4	1.9234 2	1.9931 27			1.9321 27				1.9141 15					1.9100 14						1.6974 1
	B2PLYP	1.9759 3	1.9896 3	1.9414 3	1.9783 3	1.9372 18	1.9542 3	1.9309 18	1.9316 3	1.9316 3	1.9311 3			1.9565 3	1.9506 3		1.9368 3	1.9235 2			1.7005 1
Configuration interaction	CID		1.9705 29	1.9157 27	1.9578 27	1.9121 29			1.9075 26	1.9167 12
Configuration interaction	CISD		1.9728 29	1.9167 27	1.9601 27	1.9128 28			1.9085 26	1.9179 12
Quadratic configuration interaction	QCISD	1.9262 2	1.9857 28	1.9298 25	1.9771 27	1.9258 28	1.9251 27	1.9196 27	1.9205 27	1.9173 25	1.8896 24			1.9158 20	1.8927 14		1.9074 13	1.9024 11		1.7085 1	1.6974 1
Quadratic configuration interaction	QCISD(T)					1.9293 26				1.9008 1				1.9202 14	1.9013 14
Coupled Cluster	CCD	1.9247 2	1.9805 28	1.9266 25	1.9712 27	1.9218 27	1.9210 26	1.9164 27	1.9172 27	1.9139 25	1.8870 24			1.9124 20	1.8901 14		1.9047 13	1.8954 9		1.7067 1	1.6959 1
	CCSD					1.9237 25								1.9137 14	1.8947 14
	CCSD(T)					1.9285 26				1.9004 1				1.9194 14	1.9159 13	1.9343 1	1.9141 14	1.8940 6		1.7098 1
	CCSD(T)=FULL					1.9134 13								1.9149 13	1.8816 10		1.9046 11	1.6976 1		1.7073 1	1.6932 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	1.9514 28	1.7335 2	1.9507 28	1.7314 2	1.9660 28	1.9501 28
density functional	B1B95	1.9771 14		1.9522 1		1.9576 1	1.9504 1
density functional	B3LYP	1.9849 28	1.7378 2	1.9835 28	1.7356 2	1.9889 28	1.9760 28
Moller Plesset perturbation	MP2FC	1.9878 28	1.7264 2	1.9860 28	1.7232 2	1.9971 28	1.9836 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.