National Institute of Standards and Technology

Computational Chemistry Comparison and Benchmark DataBase
Release 22	May 2022
NIST Standard Reference Database 101

I	Introduction
II	Experimental data
III	Calculated data
IV	Data comparisons
V	Cost comparisons
VI	Input and output files
VII	Tutorials and Units
VIII	Links to other sites
IX	Feedback
X	Older CCCBDB versions
XII	Geometries
XIII	Vibrations
XIV	Reaction data
XV	Entropy data
XVI	Bibliographic data
XVII	Ion data
XVIII	Bad calculations
XIX	Index of properties
XX	H-bond dimers
XXI	Oddities

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XVII.C.1. (III.D.6.)

Calculated Ionization Energy for HCl (Hydrogen chloride)

Experimental Ionization Energy is 12.744 ± 0.009 eV
Please note! These calculated ionizataion energies have the vibrational zero-point energy (zpe) included, but the zpe has NOT been scaled. Click on an entry for more details, including the ionization energy with a scaled zpe.

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Ionization Energies in eV

Methods with predefined basis sets

semi-empirical	AM1
	PM3
	PM6
composite	G2	12.700
	G3	12.704
	G3B3	12.703
	G3MP2	12.706
	G4	12.713
	CBS-Q	12.759

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Ionization Energies in eV

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-pCVDZ	cc-pCVTZ	daug-cc-pVDZ	daug-cc-pVTZ
hartree fock	HF	10.848	11.818	11.640	11.747	11.577	11.573	11.571	11.585	11.590	11.509	11.514	11.531	11.530	11.495	11.491	11.572	11.502	11.496	11.491	11.525	11.488	11.564	11.498
density functional	LSDA	12.517	9.849	13.396	13.409	13.369	13.373	13.415	13.450	13.469	13.359	13.436	13.403	13.320	13.412	13.417	13.436	13.428	13.424	13.411	13.339	13.404
	BLYP	11.732	12.573	12.499	12.552	12.489	12.490	12.560	12.595	12.609	12.467	12.567	12.528	12.428	12.526		12.577	12.559		12.526	12.446	12.520	12.573	12.556
	B1B95	11.944	12.686	12.666	12.705	12.644	12.635	12.663	12.688	12.701	12.611		12.646	12.590	12.645	12.651	12.688	12.664	12.657	12.645	12.609	12.639
	B3LYP	11.981	12.808	12.722	12.773	12.698	12.698	12.744	12.774	12.786	12.673	12.742	12.715	12.644	12.712	12.722	12.759	12.734	12.729	12.711	12.655	12.705	12.754	12.731
	B3LYPultrafine		12.808			12.698	12.699	12.744	12.773		12.672	12.742	12.715	12.643	12.712		12.758	12.734		12.711	12.655	12.705	12.754	12.731
	B3PW91	12.079	12.864	12.770	12.799	12.721	12.722	12.742	12.760	12.773	12.691	12.730	12.718	12.686	12.710		12.760	12.723		12.709	12.696	12.703	12.753	12.721
	mPW1PW91	12.048	12.811	12.730	12.767	12.664	12.664	12.687	12.703	12.734	12.651	12.691	12.678	12.627	12.650		12.722	12.685		12.667	12.656	12.661	12.716	12.684
	M06-2X	12.081	12.877	12.771	12.819	12.742	12.740	12.759	12.781	12.793	12.723	12.755	12.741	12.683	12.742		12.770	12.758		12.742	12.678	12.740	12.756	12.752
	PBEPBE	11.911	12.731	12.651	12.693	12.629	12.631	12.678	12.701	12.716	12.604	12.675	12.644	12.581	12.639	12.651	12.693	12.667	12.663	12.638	12.595	12.632	12.688	12.665
	PBEPBEultrafine		12.730			12.629	12.631	12.678	12.701		12.604	12.675	12.644	12.580	12.639		12.692	12.667		12.639	12.594	12.632	12.688	12.665
	PBE1PBE	11.987	12.700	12.700	12.743	12.659	12.806	12.682	12.701	12.714	12.628	12.669	12.652	12.618	12.643		12.696	12.661		12.642	12.627	12.636	12.690	12.659
	HSEh1PBE	11.981	12.791	12.695	12.733	12.650	12.650	12.674	12.695	12.708	12.619	12.663	12.646	12.608	12.637		12.687	12.654		12.636	12.617	12.630	12.682	12.652
	TPSSh	11.986	12.777	12.671	12.727	12.639	12.638	12.661	12.688	12.697	12.604	12.652	12.638	12.590	12.627	12.628	12.664	12.644	12.636	12.626			12.658	12.643
	wB97X-D	12.055	12.887	12.798	12.799	12.724	12.725	12.742	12.754	12.767	12.701	12.733	12.718	12.742	12.711	12.725	12.775	12.723	12.730	12.711			12.769	12.721
	B97D3	12.020	12.710	12.617	12.653	12.579	12.582	12.627	12.644	12.661	12.554	12.619	12.603	12.545	12.596	12.608	12.647	12.619	12.616	12.594			12.640	12.616
		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-pCVDZ	cc-pCVTZ	daug-cc-pVDZ	daug-cc-pVTZ
Moller Plesset perturbation	MP2	10.903	12.195	12.274	12.145	12.231	12.270	12.280	12.266	12.337	12.589	12.658	12.324	12.325	12.635	12.764	12.570	12.709	12.795	12.639	12.326	12.637	12.564	12.708
	MP2=FULL	10.901	12.197	12.276	12.145	12.233	12.274	12.283	12.264	12.335	12.602	12.667	12.323	12.330	12.642	12.775	12.575	12.718	12.806	12.653	12.340	12.660	12.569	12.716
	MP3					12.177		12.274				12.591	12.256	12.262	12.569					12.574	12.261	12.570
	MP3=FULL					12.174		12.220												12.568
	MP4		12.210			12.163				12.261		12.604	12.241	12.236	12.577		12.497	12.659		12.581	12.237	12.579
	MP4=FULL		12.209			12.162				12.254		12.604		12.237	12.577		12.498	12.662		12.586	12.244	12.593
	B2PLYP	11.579	12.556	12.512	12.516	12.481	12.493	12.524	12.539	12.569	12.578	12.645	12.517	12.474	12.613		12.632	12.655		12.615	12.480	12.610	12.627	12.652
	B2PLYP=FULL	11.578	12.557	12.513	12.516	12.482	12.494	12.525	12.538	12.568	12.582	12.647	12.517	12.475	12.615		12.634	12.657		12.618			12.629	12.654
	B2PLYP=FULLultrafine	11.579	12.556	12.513	12.516	12.482	12.495	12.525	12.538	12.568	12.582	12.648	12.517	12.475	12.615		12.634	12.657		12.618			12.629	12.654
Configuration interaction	CID		12.189	12.138	12.143	12.097			12.115			12.421		12.162	12.407					12.406	12.160	12.403	12.363	12.462
	CISD			12.131	12.136	12.088			12.111			12.409		12.153	12.396					12.394	12.152	12.392	12.355	12.450
		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-pCVDZ	cc-pCVTZ	daug-cc-pVDZ	daug-cc-pVTZ
Quadratic configuration interaction	QCISD		12.202	12.178	12.159	12.137	12.170	12.180	12.162	12.224	12.462	12.515	12.208	12.210	12.498		12.443	12.562		12.498	12.210	12.495	12.437	12.560
	QCISD(T)					12.148			12.178			12.575	12.224	12.219	12.549		12.476	12.629		12.551	12.219	12.549	12.471	12.628
	QCISD(T)=FULL					12.147		12.195				12.573		12.220	12.549	12.696	12.477	12.631	12.725	12.555			12.472	12.629
	QCISD(TQ)					12.147		12.195				12.571		12.219	12.545	12.690	12.476	12.625
Coupled Cluster	CCD		12.210	12.184	12.166	12.146	12.180	12.187	12.167	12.230	12.478	12.528	12.217	12.221	12.511		12.452	12.576		12.512	12.219	12.510	12.446	12.575
	CCSD					12.137	12.170	12.179	12.160	12.223	12.463	12.515	12.208	12.211	12.498	12.626	12.442	12.563	12.649	12.499	12.210	12.496	12.436	12.561
	CCSD=FULL					12.135					12.467	12.512	12.203	12.212	12.497	12.626	12.443	12.564	12.650	12.501	12.216	12.507	12.437	12.561
	CCSD(T)					12.148	12.184	12.196	12.178	12.244	12.501	12.575	12.224	12.219	12.549	12.695	12.476	12.629	12.724	12.552	12.219	12.549	12.471	12.628
	CCSD(T)=FULL					148.721						12.573	12.219	12.220	12.549	12.697	12.477	12.632	12.726	12.555	12.226	12.562	12.472	12.630
		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-pCVDZ	cc-pCVTZ	daug-cc-pVDZ	daug-cc-pVTZ

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Ionization Energies in eV

Methods with effective core potentials (select basis sets)

		CEP-31G	CEP-31G*	CEP-121G	CEP-121G*	LANL2DZ	SDD	cc-pVTZ-PP	aug-cc-pVTZ-PP	Def2TZVPP
hartree fock	HF	11.790	11.578	11.719	11.531	11.923	11.737			11.489
density functional	BLYP									12.516
	B1B95									12.640
	B3LYP	12.778	12.669	12.699	12.616	12.852	12.745			12.702
	B3LYPultrafine									12.702
	B3PW91									12.703
	mPW1PW91									12.662
	M06-2X									12.737
	PBEPBE									12.631
	PBEPBEultrafine									12.632
	PBE1PBE									12.636
	HSEh1PBE									12.630
	TPSSh									12.620
	wB97X-D	12.784	12.673	12.708	12.624	12.941	12.846			12.706
	B97D3									12.586
Moller Plesset perturbation	MP2	12.114	12.297	12.097	12.289	12.201	12.087			12.640
	MP2=FULL									12.658
	B2PLYP									12.609
	B2PLYP=FULL									12.614
	B2PLYP=FULLultrafine									12.614
Configuration interaction	CID									12.408
	CISD									12.396
Quadratic configuration interaction	QCISD									12.500
	QCISD(T)									12.553
	QCISD(T)=FULL									12.559
Coupled Cluster	CCD									12.514
	CCSD									12.500
	CCSD=FULL									12.505
	CCSD(T)									12.553
	CCSD(T)=FULL									12.559

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.