III.G.1.a.

Comparison of levels of theory for H-Se

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	2.2203 4
	PM3	1.4873 8
	PM6	1.4684 9
composite	G2	1.4746 9
composite	CBS-Q	1.4776 4

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
hartree fock	HF	1.4620 9	1.4798 9	1.4721 9	1.4618 9	1.4746 9	1.4517 9	1.4513 9	1.4710 9	1.4619 9	1.4607 6	1.4541 4	1.4610 9	1.4662 9	1.4628 9	1.4614 9	1.4664 9	1.4686 5	1.4614 9
hartree fock	ROHF	1.4706 3	1.4774 3	1.4722 3	1.4589 3	1.4762 4	1.4524 3	1.4522 3	1.4710 3	1.4630 3	1.4582 3			1.4663 3	1.4638 3	1.4658 2	1.4678 3	1.4638 3	1.4659 2
density functional	LSDA	1.4900 9	1.5102 9	1.4989 9	1.4978 9	1.5025 9	1.4778 9	1.4785 9	1.4973 9	1.4887 9	1.4808 9			1.4961 9	1.4857 8	1.4944 4	1.4957 9	1.4951 4	1.4942 4
	SVWN		1.5159 9			1.5012 7		1.4785 9
	BLYP	1.4967 9	1.5217 9	1.5076 9	1.5053 9	1.5112 9	1.4859 9	1.4867 9	1.5056 9	1.4972 8	1.4900 8			1.5055 9	1.4953 9
	B1B95	1.4867 8	1.4922 8	1.4873 8	1.4815 9	1.4958 5	1.4648 9	1.4637 7	1.4852 9	1.4763 9	1.4692 9			1.4824 9	1.4747 9	1.4818 5	1.4764 6	1.4825 5	1.4822 3
	B3LYP	1.4866 9	1.5063 9	1.4938 9	1.4894 9	1.4971 9	1.4721 9	1.4724 9	1.4918 9	1.4835 8	1.4767 8		1.4817 9	1.4907 9	1.4820 9	1.4808 9	1.4898 9	1.4817 9	1.4807 9
	B3LYPultrafine					1.5032 5
	B3PW91	1.4867 9	1.5044 9	1.4907 9	1.4853 9	1.4927 9	1.4683 9	1.4685 9	1.4888 9	1.4807 8	1.4733 8			1.4859 9	1.4794 9
	mPW1PW91	1.4840 9	1.5008 9	1.4876 9	1.4816 9	1.4895 9	1.4652 9	1.4656 9	1.4860 9	1.4778 8	1.4703 8			1.4828 9	1.4767 9
	M06-2X					1.4874 9
	PBEPBE	1.4969 9	1.5199 9	1.5039 9	1.5005 9	1.5059 9	1.4867 9	1.4817 9	1.5021 9	1.4941 8	1.4844 9			1.4996 9	1.4925 9	1.4998 5	1.4937 5	1.4870 5	1.4996 5
	HSEh1PBE					1.4905 8
Moller Plesset perturbation	MP2FC	1.4744 8	1.4968 9	1.4858 9	1.4800 9	1.4913 9	1.4573 9	1.4577 9	1.4865 9	1.4685 8	1.4645 8		1.4609 9	1.4721 9	1.4527 5	1.4504 1	1.4747 9	1.4583 1	1.4488 1
	MP2FU	1.4743 8	1.4967 9	1.4858 9	1.4790 9	1.4905 9	1.4551 9	1.4554 9	1.4846 9	1.4643 8	1.4552 8			1.4710 9	1.4468 5	1.4450 1	1.4696 4
	ROMP2	1.4989 2	1.4950 2	1.4907 2	1.4762 2	1.4952 2	1.4626 2	1.4624 2	1.4904 2	1.4738 2	1.4705 2			1.4770 2	1.4653 2	1.4623 2	1.4802 2	1.4660 2	1.4613 2
	MP3					1.5039 5
	MP4		1.5087 9			1.5009 9				1.4803 5					1.4641 5
	B2PLYP					1.4924 9		1.4653 9
Configuration interaction	CID		1.5118 6	1.4967 6	1.4927 6	1.4965 9			1.4981 6
Configuration interaction	CISD		1.5148 6	1.4977 6	1.4950 6	1.4975 9			1.4994 6
Quadratic configuration interaction	QCISD	1.4734 3	1.5132 9	1.4963 9	1.4936 9	1.5018 9	1.4637 9	1.4690 6	1.4981 9	1.4749 8	1.4701 8			1.4793 9	1.4678 8
Quadratic configuration interaction	QCISD(T)					1.5037 9								1.4858 6	1.4699 8		1.4883 6	1.4764 5
Coupled Cluster	CCD	1.4728 3	1.5103 9	1.4949 9	1.4913 9	1.5004 9	1.4623 9	1.4675 6	1.4965 9	1.4735 8	1.4689 8			1.4778 9	1.4705 6		1.4867 5	1.4727 5
	CCSD					1.5036 7
	CCSD(T)		1.5039 2	1.4872 2	1.4855 2	1.4954 4		1.4552 2	1.4889 2			1.4734 1		1.4819 8	1.4699 8	1.4770 1	1.4845 8	1.4763 5	1.4758 1
	CCSD(T)=FULL					1.5053 3										1.4726 1			1.4695 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	1.4874 8		1.4858 8		1.4845 9	1.4766 9
density functional	B1B95	1.5066 4
	B3LYP	1.5178 9		1.5158 9		1.5096 9	1.5040 9
	PBEPBE	1.5261 1		1.5243 1		1.5242 1	1.5145 1
Moller Plesset perturbation	MP2FC	1.5100 9		1.5082 9		1.5010 9	1.4955 9

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.