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 N (Nitrogen atom)

Experimental Ionization Energy is 14.53414 eV

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Ionization Energies in eV

Methods with predefined basis sets

semi-empirical	PM3
	PM6
composite	G1	14.470
	G2MP2	14.431
	G2	14.476
	G3	11.954
	G3B3	14.509
	G3MP2	14.469
	G4	14.504
	CBS-Q	14.492

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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)	6-311+G(3df,2pd)	TZVP	cc-pVDZ	cc-pVTZ	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	daug-cc-pVTZ
hartree fock	HF	12.963	13.990	13.990	14.055	13.966	13.966	13.957	13.930	13.930	13.921	13.912		13.914	13.895	13.892	13.893	13.930	13.897	13.894	13.896
	ROHF	12.963	13.981	13.981	14.027	14.026	14.026	14.008	13.989	13.989	13.995	13.974	13.974	13.959	13.964	13.960	13.955	13.987	13.959	13.956
density functional	LSDA		15.251	15.251			15.426	15.500		15.438	15.391	15.478	15.478	15.449	15.339	15.436	15.448	15.471	15.461	15.458
	BLYP	13.149	14.262	14.262	14.473	14.456	14.456	14.553	14.449	14.449	14.420	14.513	14.513	14.491	14.366	14.463	14.483	14.526	14.503	14.500
	B1B95	13.532	14.499	14.499	14.636	14.611	14.611	14.653	14.578	14.578	14.584	14.599	14.599	14.583	14.536	14.572	14.576	14.630	14.592	14.584
	B3LYP	13.431	14.507	14.507	14.679	14.657	14.657	14.718	14.637	14.637	14.619	14.675		14.657	14.572	14.638	14.650	14.691	14.663	14.660
	B3LYPultrafine	13.431	14.507			14.657	14.657	14.717	14.637		14.619	14.675		14.657	14.572	14.638	14.650	14.691	14.663	14.660
	B3PW91	13.628	14.719	14.719	14.826	14.791	14.791	14.830	14.767	14.767	14.759	14.786	14.786	14.771	14.719	14.759	14.764	14.807	14.776	14.773
	mPW1PW91	13.621	14.690	14.690	14.789	14.751	14.751	14.791	14.723	14.723	14.720	14.746	14.746	14.739	14.681	14.720	14.731	14.770	14.741
	M06-2X	13.452	14.455	14.455	14.580	14.566	14.566	14.600	14.562	14.562	14.532	14.571	14.573	14.539	14.478	14.553	14.529	14.570	14.565	14.533
	PBEPBE	13.437	14.552	14.552	14.728	14.698	14.698	14.779	14.682	14.682	14.669	14.738		14.721	14.619	14.696	14.714	14.757	14.734	14.731
	PBEPBEultrafine	13.437	14.552	14.552	14.728	14.698	14.698	14.779	14.682	14.682	14.669	14.738		14.721	14.619	14.696	14.714	14.757	14.734	14.731
	PBE1PBE	13.556	14.627	14.627	14.751	14.714	14.714	14.755	14.685	14.685	14.683	14.711	14.711	14.701	14.642	14.684	14.693	14.733	14.706	14.702
	HSEh1PBE	13.544	14.630	14.630	14.746	14.708	14.708	14.749	14.680	14.680	14.676	14.704	14.704	14.697	14.633	14.680	14.689	14.725	14.700	14.698
	TPSSh					14.659		14.705			14.627					14.653
	wB97X-D			14.626		14.646		14.678		14.610				14.613	14.752	14.589			14.606
	B97D3		14.646			14.720		14.768		14.689		14.731		14.751		14.720			14.752
		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)	6-311+G(3df,2pd)	TZVP	cc-pVDZ	cc-pVTZ	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	daug-cc-pVTZ
Moller Plesset perturbation	MP2	12.672	14.015	14.015	14.160	14.423	14.423	14.432	14.411	14.411	14.546	14.594		14.376	14.354	14.556	14.605	14.478	14.590	14.619
	MP2=FULL	12.669	14.013	14.013	14.158	14.427	14.427	14.436	14.418	14.418	14.555	14.611	14.611	14.384	14.356	14.572	14.628	14.481	14.606	14.642
	ROMP2	12.963	14.733	14.733	14.812	16.046	16.046	16.061	16.162	16.162	16.470				15.951	16.650		16.097
	MP3	12.529	13.918	13.918	14.083	14.383	14.383	14.393	14.363	14.363	14.528	14.568	14.568	14.321	14.315	14.530	14.574	14.459	14.563	14.584
	MP3=FULL					14.387		14.398
	MP4	12.460	13.856	13.856	14.027	14.323	14.323	14.337	14.303	14.303	14.484	14.529	14.529	14.264	14.254	14.488	14.539	14.413	14.526	14.550
	MP4=FULL	12.457	13.856	13.856	14.027	14.328	14.328	14.342	14.312	14.312	14.493	14.548	14.548	14.273	14.257	14.505	14.563	14.416	14.543	14.575
Configuration interaction	CID	12.400	13.802	13.802	13.968	14.261	14.261	14.271	14.239	14.239	14.405	14.442	14.442	14.200	14.192	14.404	14.448	14.336	14.436	14.458
	CISD	12.400	13.801	13.801	13.969	14.253	14.253	14.267	14.233	14.233	14.396	14.437	14.437	14.197	14.184	14.398	14.443	14.333	14.432	14.453
		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)	6-311+G(3df,2pd)	TZVP	cc-pVDZ	cc-pVTZ	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	daug-cc-pVTZ
Quadratic configuration interaction	QCISD	12.400	13.803	13.803	13.974	14.264	14.264	14.279	14.245	14.245	14.411	14.454	14.454	14.209	14.195	14.414	14.460	14.347	14.449	14.471
	QCISD(T)	12.400	13.796	13.796	13.970	14.262	14.262	14.281	14.243	14.243	14.427	14.476	14.476	14.210	14.191	14.432	14.487	14.358	14.474	14.500
	QCISD(TQ)		13.794	13.795	13.970	14.262	13.492	14.281	14.241	14.244	14.430			14.210	14.191	14.433		14.358
Coupled Cluster	CCD	12.400	13.804	13.804	13.972	14.271	14.271	14.283	14.251	14.251	14.419	14.458	14.458	14.211	14.203	14.420		14.350	14.453
	CCSD		13.803	13.803	13.973	14.264	14.264	14.279	14.245	14.245	14.411	14.454	14.454	14.208	14.195	14.414	14.461	14.346	14.449	14.471
	CCSD=FULL		13.804	13.804	13.973	14.269	14.269	14.285	14.256	14.256	14.421	14.475	14.475	14.219	14.198	14.432	14.487	14.350	14.467	14.498
	CCSD(T)		13.796	13.796	13.970	14.262	14.262	14.280	14.243	14.243	14.427	14.476		14.210	14.191	14.433	14.487	14.357	14.474	14.500
	CCSD(T)=FULL		13.796	13.796	13.969	14.267	14.267		14.253	14.253	14.436	14.496	14.496	14.219	14.195	14.449	14.512	14.360	14.491	14.525
		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)	6-311+G(3df,2pd)	TZVP	cc-pVDZ	cc-pVTZ	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	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	14.116	13.992	14.003	13.896	14.038	14.026			13.898
	ROHF	14.097	14.070	13.946	13.939	14.010	13.996
density functional	LSDA	15.377	15.332	15.290	15.260	15.491	15.467
	BLYP	14.415	14.353	14.307	14.269	14.542	14.504
	B1B95	14.794		14.682		14.658	14.631
	B3LYP	14.640	14.575	14.524	14.481	14.728	14.696			14.652
	B3LYPultrafine	14.641	14.576	14.524			14.696
	B3PW91	14.852	14.787	14.726	14.679	14.859	14.829
	mPW1PW91	14.851	14.781	14.722	14.671	14.827	14.797
	M06-2X	15.073	15.053	14.983	14.974	14.639	14.613
	PBEPBE	14.809	14.741	14.696	14.648	14.792	14.757			14.716
	PBEPBEultrafine	14.809	14.741	14.696	14.648	14.792	14.757
	PBE1PBE	14.845	14.773	14.719	14.666	14.790	14.760
	HSEh1PBE	14.832	14.759	14.707	14.654	14.786	14.757
Moller Plesset perturbation	MP2	14.121	14.375	14.081	14.332	14.130	14.123			14.564
	MP2=FULL	14.121	14.375	14.081	14.332	14.128	14.124
	MP3	14.029	14.323	13.999	14.281	14.053	14.047
	MP4	13.976	14.264	13.953	14.223	14.004	13.998
	MP4=FULL	13.976	14.264	13.953	14.223	14.003	14.000
Configuration interaction	CID	13.910	14.202	13.887	14.157	13.937	13.931
	CISD	13.918	14.195	13.897	14.152	13.944	13.938
Quadratic configuration interaction	QCISD	13.920	14.204	13.902	14.163	13.949	13.943
	QCISD(T)	13.921	14.204	13.905	14.167	13.949	13.944
	QCISD(TQ)	13.920	13.550	13.904	14.165	13.945	4.160
Coupled Cluster	CCD	13.912	14.211	13.891	14.168	13.941	13.936
	CCSD	13.917	14.203	13.899	14.163	13.946	13.941
	CCSD=FULL	13.917	14.203	13.899	14.163	13.946	13.943
	CCSD(T)	13.920	14.204	13.903	14.167	13.948	13.943
	CCSD(T)=FULL	13.920	14.204	13.903	14.167	13.948	13.945

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.