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
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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 CHNCH₂ (2H-Azirine)

Experimental Ionization Energy is 10.1 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

composite	G2	9.931
	G3	9.906
	G3B3	9.981
	G4	9.966
	CBS-Q	9.886

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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	aug-cc-pVDZ	aug-cc-pVTZ	daug-cc-pVTZ
hartree fock	HF					8.736	8.725	8.786	8.717	8.704	8.649	8.729	8.735	8.709	8.702	8.742	8.717
density functional	BLYP	8.570			9.600	9.535	9.532	9.718	9.641	9.639	9.495	9.718	9.716	9.541	9.671	9.717	9.713
	B1B95	8.865	9.730	9.730	9.865	9.784	9.784	9.888	9.825	9.820	9.737	9.866	9.870	9.776	9.831	9.870	9.857
	B3LYP	8.817			9.863	9.784	9.779	9.926	9.860	9.856	9.737	9.917	9.919	9.780	9.879	9.915	9.911
	B3LYPultrafine					9.784	9.779	9.926	9.860		9.737	9.917	9.919	9.780	9.879	9.915	9.911
	B3PW91	8.915			9.944	9.852	9.848	9.954	9.904	9.899	9.798	9.933	9.941	9.844	9.903	9.932	9.926
	mPW1PW91	8.889			9.928	9.831	9.825	9.933	9.876	9.870	9.773	9.908	9.919	9.823	9.875	9.909	9.902
	M06-2X	8.928	9.862	9.862	10.003	9.916	9.903	10.008	9.977	9.966	9.870	10.004	10.002	9.891	9.991	9.982	10.012
	PBEPBE	8.773	9.672	9.672	9.823	9.738	9.734	9.887	9.816	9.812	9.694	9.875	9.878	9.743	9.834	9.878	9.871
	PBEPBEultrafine		9.672			9.739	9.734	9.887	9.816		9.694	9.875	9.878	9.743	9.834	9.878	9.871
	PBE1PBE	8.842	9.778	9.778	9.914	9.814	9.814	9.918	9.859	9.852	9.759	9.893	9.903	9.807	9.862	9.897	9.888
	HSEh1PBE	8.831			9.901	9.803	9.797	9.909	9.850	9.844	9.747	9.886	9.896	9.794	9.856	9.887	9.881
	TPSSh	8.792			9.815	9.723	9.718	9.829	9.773	9.768	9.664	9.806	9.819	9.713	9.779	9.803	9.808
	wB97X-D	8.851	9.816	9.816	9.914	9.815	9.814	9.917	9.862	9.859	9.761	9.889	9.894	9.807	9.850	9.888	9.872
	B97D3	8.775			9.741	9.676	9.674	9.811	9.739	9.738	9.623	9.792	9.797	9.684	9.751	9.798	9.786	9.786
		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	aug-cc-pVDZ	aug-cc-pVTZ	daug-cc-pVTZ
Moller Plesset perturbation	MP2				9.810	9.759	9.827	9.969	9.821	9.896	9.915	10.103	9.934	9.841	10.072	10.030	10.144
	MP2=FULL				9.812	9.762	9.830	9.972	9.829	9.905	9.921	10.117	9.939	9.846	10.083	10.033	10.148
	MP3					9.651		9.830				9.955	9.788	9.732	9.930
	MP3=FULL				9.704	9.654	9.727	9.833	9.692	9.773	9.814	9.972	9.793	9.737	9.946	9.888
	MP4		6.849			9.683				9.826		10.039	9.865	9.763	10.004	9.956
	MP4=FULL		6.848			9.685				9.834		10.055		9.767		9.958	10.079
	B2PLYP	8.418			9.676	9.669	9.684	9.830	9.740	9.759	9.690	9.875	9.817	9.692	9.836	9.845	9.881
	B2PLYP=FULL	8.419			9.677	9.671	9.686	9.832	9.744	9.762	9.695	9.882	9.819	9.694	9.842	9.846	9.886
	B2PLYP=FULLultrafine	8.419			9.676	9.673	9.686	9.832	9.744	9.763	9.695	9.882	9.819	9.694	9.842	9.846	9.887
Configuration interaction	CID				9.514	9.461			9.479			9.678		9.508	9.654
	CISD				9.405	9.430			9.453			9.656		9.478	9.631
		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	aug-cc-pVDZ	aug-cc-pVTZ	daug-cc-pVTZ
Quadratic configuration interaction	QCISD				9.369	9.530	9.592	9.708	9.580	9.648	9.689	9.853	9.681	9.599	9.821	9.754
	QCISD(T)					9.553			9.616			9.918	9.725	9.631	9.881	9.810	9.949
	QCISD(T)=FULL					9.559		9.751				9.938		9.637	9.901	9.815	9.964
Coupled Cluster	CCD				9.711	9.656	9.724	9.832	9.689	9.763	9.792	9.942	9.788	9.728	9.916	9.875
	CCSD					9.547	9.611	9.725	9.596	9.666	9.705	9.867	9.697	9.620	9.836	9.773
	CCSD=FULL					9.553					9.718		9.704	9.626	9.857	9.778	9.910
	CCSD(T)					9.565	9.631	9.757	9.628		9.744	9.929	9.738	9.644	9.893	9.824	9.960
	CCSD(T)=FULL					9.571						9.948	9.745	9.650	9.912	9.828	9.974
		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	aug-cc-pVDZ	aug-cc-pVTZ	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		8.647		8.687					8.715
density functional	BLYP									9.698
	B1B95									9.852
	B3LYP	9.765	9.675	9.820	9.740	9.881	9.875			9.900
	B3LYPultrafine									9.900
	B3PW91									9.918
	mPW1PW91									9.894
	M06-2X									9.989
	PBEPBE									9.857
	PBEPBEultrafine									9.857
	PBE1PBE									9.880
	HSEh1PBE									9.873
	TPSSh									9.796
	wB97X-D	9.772	9.679	9.829	9.747	9.907	9.903			9.873
	B97D3									9.776
Moller Plesset perturbation	MP2		9.749		9.807					10.098
	MP2=FULL									10.101
	MP3									9.951
	MP3=FULL									9.955
	MP4									10.029
	MP4=FULL									10.033
	B2PLYP									9.859
	B2PLYP=FULL									9.862
	B2PLYP=FULLultrafine									9.862
Configuration interaction	CID									9.672
	CISD									9.649
Quadratic configuration interaction	QCISD									9.842
	QCISD(T)									9.904
	QCISD(T)=FULL									9.912
Coupled Cluster	CCD									9.936
	CCSD									9.856
	CCSD=FULL									9.864
	CCSD(T)									9.916
	CCSD(T)=FULL									9.922

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.