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 HSe (Selenium monohydride)

Experimental Ionization Energy is 9.845 ± 0.003 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	PM3
	PM6
composite	G2	9.684
	G3	9.728
	G3B3	9.727
	G4	9.748
	CBS-Q	9.787

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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	daug-cc-pVDZ	daug-cc-pVTZ
hartree fock	HF	6.615	8.529	8.490	8.748	8.596	8.605	8.642	8.596	8.606	8.636	8.637	8.585	8.613	8.626	8.632	8.641	8.635	8.635	8.636	8.634
	ROHF		8.587	8.549	8.806	8.656	8.665	8.694	8.663	8.672		8.692	8.653	8.672	8.680	8.684	8.701	8.686	8.686	8.696	8.686
density functional	LSDA	8.419	10.247	10.247	10.416	10.356	10.368	10.431	10.431	10.446	10.402		10.428	10.391	10.466		10.459	10.470
	BLYP	7.676	9.371	9.426	9.600	9.538	9.546	9.638	9.644	9.655	9.574	9.693	9.640	9.574	9.672		9.670	9.682		9.667	9.680
	B1B95	7.892	9.492	9.492	9.701	9.607	9.607	9.670	9.642	9.654	9.648	9.688	9.636	9.638	9.669		9.684	9.676		9.680	9.676
	B3LYP	7.902	9.593	9.627	9.815	9.733	9.742	9.812	9.807	9.818	9.770	9.852	9.802	9.764	9.835	9.840	9.836	9.842	9.843	9.833	9.842
	B3LYPultrafine		9.591			9.732	9.743	9.814	9.806		9.771	9.852	9.803	9.764	9.835		9.836	9.842		9.833	9.842
	B3PW91	7.939	9.597	9.617	9.804	9.708	9.718	9.763	9.741	9.753	9.746	9.787	9.740	9.737	9.774		9.778	9.780		9.774	9.780
	mPW1PW91	7.903	9.561	9.575	9.764	9.665	9.675	9.724	9.698	9.710	9.704	9.746	9.700	9.694	9.735		9.737	9.743		9.733	9.743
	M06-2X	7.821	9.490	9.442	9.704	9.584	9.594	9.644	9.604	9.614	9.610	9.638	9.576	9.587	9.592		9.626	9.599		9.617	9.596
	PBEPBE	7.799	9.462	9.500	9.672	9.600	9.609	9.680	9.672	9.683	9.636	9.724	9.669	9.633	9.705		9.705	9.715		9.699	9.714
	PBEPBEultrafine		9.457			9.598	9.610	9.681	9.669		9.636	9.724	9.669	9.632	9.704		9.702	9.714		9.699	9.714
	PBE1PBE	7.852	9.540	9.540	9.729	9.631	9.631	9.691	9.669	9.681	9.670	9.718	9.668	9.660	9.704		9.705	9.711		9.701	9.711
	HSEh1PBE	7.843	11.465	9.567	9.747	9.650	9.661	9.710	9.694	9.706	9.691	9.743	9.696	9.681	9.878		9.728	9.740		9.724	9.739
	TPSSh	7.835	9.538	9.550	9.741	9.645	9.653	9.699	9.683	9.691	9.676	9.725	9.681	9.673	9.715	9.718	9.712	9.722	9.721	9.708	9.723
	wB97X-D	7.904	9.682	9.684	9.844	9.734	9.746	9.791	9.762	9.777	9.780	9.813	9.776	9.781	9.805	9.813	9.822	9.810	9.814	9.819	9.812
	B97D3	7.704	9.368	9.395	9.613	9.531	9.543	9.613	9.618	9.630	9.569	9.667	9.622	9.600	9.650	9.657	9.664	9.654	9.660	9.660	9.654
		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	daug-cc-pVDZ	daug-cc-pVTZ
Moller Plesset perturbation	MP2		8.727	9.066	8.967	9.169	9.207	9.252	9.202	9.252	9.421	9.492	9.256	9.218	9.537	9.668	9.361	9.589	9.694	9.358	9.591
	MP2=FULL		8.727	9.067	8.964	9.192	9.231	9.276	9.247	9.299	9.462	9.552	9.246	9.220	9.536	9.663	9.362	9.589	9.689	9.359	9.590
	ROMP2	6.648	9.070	9.070	8.980	9.179	9.214	9.259	9.213	9.260	9.425	9.497	9.256	9.219	9.532		9.363			9.360	9.586
	MP3					9.184		9.269				9.547	9.240	9.214	9.561
	MP3=FULL		8.748	9.062	8.989	9.191	9.232	9.277	9.220	9.274	9.491	9.559	9.226	9.212	9.553		9.369	9.606		9.366	9.607
	MP4		8.750			9.173				9.264		9.567	9.249	9.204	9.593		9.377	9.652		9.375	9.653
	MP4=FULL		8.748			9.184				9.294		9.607		9.204	9.590		9.378	9.650		9.375	9.652
	B2PLYP		9.270	9.397	9.495	9.500	9.519	9.578	9.555	9.578	9.608	9.679	9.568	9.534	9.683		9.631	9.706		9.629	9.706
	B2PLYP=FULL		9.270	9.397	9.494	9.508	9.527	9.586	9.570	9.594	9.622	9.699	9.565	9.535	9.682		9.632	9.706		9.629	9.706
	B2PLYP=FULLultrafine		9.269	9.397	9.495	9.508	9.528	9.587	9.570	9.594	9.623	9.699	9.565	9.535	9.682		9.632	9.706		9.629	9.706
Configuration interaction	CID		8.736	8.993	8.980	9.112			9.138			9.437		9.138	9.434					9.269	9.477
	CISD		8.726	8.988	8.971	9.106			9.131			9.430		9.130	9.428					9.264	9.471
		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	daug-cc-pVDZ	daug-cc-pVTZ
Quadratic configuration interaction	QCISD		8.736	9.036	8.982	9.153	9.190	9.235	9.184	9.233	9.449	9.512	9.214	9.181	9.535		9.337	9.585		9.334
	QCISD(T)					9.160			9.199			9.554	9.233	9.190	9.578		9.364	9.637		9.362	9.638
	QCISD(T)=FULL					9.170		9.257				9.585			9.572	9.707	9.364	9.633	9.730	9.361	9.634
Coupled Cluster	CCD		8.747	9.041	8.992	9.158	9.196	9.242	9.189	9.240	9.454	9.518	9.220	9.188	9.539		9.340	9.589		9.337	9.590
	CCSD					9.152	9.189	9.235	9.184	9.233	9.449	9.512	9.214	9.181	9.534	9.659	9.336	9.584		9.333	9.586
	CCSD=FULL					9.161					9.468	9.537	9.200	9.180	9.527	9.647	9.334	9.578	9.667	9.331	9.579
	CCSD(T)					9.159	9.198	9.246	9.199	9.251	9.484	9.555	9.233	9.190	9.578	9.715	9.364	9.637		9.361	9.638
	CCSD(T)=FULL					9.170						9.585	9.221		9.572		9.363			9.360	9.635
		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	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	8.649		8.644		8.740	8.712	8.606		8.627
	ROHF							8.657		8.681
density functional	LSDA							10.409
	BLYP							9.618		9.669
	B1B95							9.622		9.671
	B3LYP	9.800		9.802		9.840	9.849	9.789		9.834
	B3LYPultrafine							9.789		9.834
	B3PW91							9.726		9.776
	mPW1PW91							9.687		9.737
	M06-2X							9.536		9.611
	PBEPBE							9.647		9.704
	PBEPBEultrafine							9.647		9.704
	PBE1PBE							9.656		9.705
	HSEh1PBE							9.687		9.734
	TPSSh							9.667		9.714
	wB97X-D	9.795		9.792		9.878	9.832	9.767		9.815
	B97D3							9.605		9.653
Moller Plesset perturbation	MP2	8.845		8.840		8.910	8.903	9.522		9.542
	MP2=FULL							9.522		9.535
	ROMP2									9.537
	MP3							9.544		9.562
	MP3=FULL							9.538		9.549
	MP4							9.577		9.597
	MP4=FULL							9.576		9.590
	B2PLYP							9.650		9.684
	B2PLYP=FULL							9.650		9.682
	B2PLYP=FULLultrafine							9.650		9.682
Configuration interaction	CID							9.418		9.421
	CISD							9.414		9.415
Quadratic configuration interaction	QCISD							9.520		9.537
	QCISD(T)							9.563		9.581
	QCISD(T)=FULL							9.559		9.571
Coupled Cluster	CCD							9.523		9.541
	CCSD							9.519		9.536
	CCSD=FULL							9.514		9.525
	CCSD(T)							9.563		9.581
	CCSD(T)=FULL							9.560		9.571

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.