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
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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 GeH (germylidene)

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	7.648
	G3	7.789
	G3B3	7.795
	G4	7.782
	CBS-Q	7.790

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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-pVTZ
hartree fock	HF	4.563	7.131	7.279	7.322	7.325	7.314	7.328	7.287	7.278	7.316		7.280	7.286	7.293	7.295	7.291	7.295	7.295	7.295
density functional	LSDA	6.149		8.293	8.289	8.318	8.318	8.341	8.323	8.324	8.305			8.313	8.327			8.327
	BLYP	5.484	7.400	7.587	7.578	7.611	7.608	7.645	7.637	7.636	7.597		7.615	7.608	7.634		7.645	7.639
	B1B95	5.390		7.613	7.648	7.656	7.656	7.674	7.644	7.641	7.642		7.630	7.637	7.636		7.652	7.639
	B3LYP	5.494	7.603	7.777	7.787	7.806	7.802	7.829	7.813	7.811	7.793		7.799	7.797	7.812	7.808	7.821	7.814	7.809
	B3LYPultrafine		7.604			7.807	7.803	7.830	7.813				7.800	7.799	7.810		7.823	7.812
	B3PW91	5.574	7.676	7.846	7.854	7.874	7.871	7.888	7.858	7.856	7.854		7.850	7.853	7.858		7.862	7.860
	mPW1PW91	5.532	7.667	7.837	7.846	7.868	7.865	7.883	7.854	7.851	7.847		7.839	7.843	7.852		7.854	7.855
	M06-2X	5.432	7.604	7.710	7.784	7.763	7.755	7.771	7.724	7.714	7.749	7.727	7.701	7.729	7.705		7.734	7.708
	PBEPBE	5.697	7.571	7.753	7.741	7.778	7.776	7.805	7.783	7.782	7.758		7.764	7.764	7.778		7.789	7.783
	PBEPBEultrafine		7.574			7.781	7.778	7.806	7.785				7.766	7.767	7.777		7.792	7.781
	PBE1PBE	5.492		7.806	7.816	7.837	7.837	7.853	7.824	7.821	7.818		7.811	7.815	7.821		7.827	7.823
	HSEh1PBE	5.487	7.639	7.808	7.813	7.833	7.830	7.849	7.821	7.818	7.814		7.808	7.813	7.820		7.825	7.822
	TPSSh	5.627	7.643	7.813	7.797	7.828	7.825	7.841	7.807	7.804	7.798		7.789	7.797	7.809	7.806	7.805	7.813	7.807
	wB97X-D	5.418	7.539	7.688	7.709	7.706	7.703	7.720	7.680	7.679	7.688		7.674	7.676	7.677	7.677	7.687	7.678	7.678
	B97D3											7.716								7.721
		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-pVTZ
Moller Plesset perturbation	MP2	4.347	7.049	7.473	7.247	7.488	7.491	7.507	7.464	7.475	7.558		7.541	7.505	7.652	7.684	7.545	7.671	7.694
	MP2=FULL	4.345	7.046	7.471	7.229	7.509	7.513	7.529	7.524	7.535	7.598		7.528	7.504	7.644	7.663	7.543	7.662	7.673
	MP3					7.508		7.128					7.533	7.514	7.671
	MP3=FULL		7.000	7.478	7.179	7.518	7.522	7.538	7.502	7.514	7.619		7.509	7.511	7.655		7.559	7.673
	MP4		6.979			7.512				7.505			7.555	7.520	7.704		7.576	7.726
	MP4=FULL		6.977			7.527				7.555				7.519	7.697		7.573	7.717
	B2PLYP	4.996	7.358	7.620	7.550	7.644	7.642	7.664	7.636	7.638	7.660		7.656	7.644	7.703		7.673	7.711
	B2PLYP=FULL	4.996	7.357	7.620	7.544	7.654	7.652	7.674	7.660	7.662	7.678		7.652	7.644	7.701		7.672	7.709
	B2PLYP=FULLultrafine	4.997	7.357	7.620	7.544	7.655	7.652	7.674	7.660	7.661	7.677		7.652	7.644	7.700		7.673	7.707
Configuration interaction	CID		6.977	7.451	7.174	7.480			7.457
	CISD		6.974	7.464	7.171	7.494			7.470
		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-pVTZ
Quadratic configuration interaction	QCISD		6.965	7.479	7.162	7.504	7.505	7.521	7.481	7.488	7.589		7.534	7.503	7.670		7.554	7.689
	QCISD(T)					7.517			7.496				7.548	7.518	7.702		7.576	7.724
	QCISD(T)=FULL					7.529		7.547							7.690	7.720	7.573	7.711	7.728
	QCISD(TQ)					7.519		7.538						7.519	7.702	7.739	7.578	7.725	7.748
	QCISD(TQ)=FULL					7.530		7.548						7.516		7.718	7.574	7.710
Coupled Cluster	CCD		6.968	7.462	7.165	7.488	7.491	7.507	7.465	7.475	7.571		7.516	7.489	7.647		7.537	7.665
	CCSD					7.502					7.587		7.531	7.501	7.667	7.701	7.552	7.686	7.708
	CCSD=FULL					7.514					7.619		7.515	7.499	7.655	7.681	7.548	7.673	7.687
	CCSD(T)					7.516	7.517		7.495				7.547	7.517	7.700	7.739	7.575	7.722
	CCSD(T)=FULL					7.528							7.528		7.688		7.571	7.709
		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-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	7.351		7.355		7.405	7.314			7.292
density functional	B3LYP	7.876		7.882		7.911	7.856			7.802
	PBEPBE									7.768
	wB97X-D	7.803		7.805		7.875	7.799
Moller Plesset perturbation	MP2	7.252		7.259		7.279	7.201			7.659

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.