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 F₂ (Fluorine diatomic)

Experimental Ionization Energy is 15.697 ± 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
composite	G2	15.977
	G3	15.938
	G3B3	15.762
	G3MP2	15.998
	G4	15.716
	CBS-Q	16.140

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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	daug-cc-pVDZ	daug-cc-pVTZ
hartree fock	HF	12.207	16.021	16.021	16.365	15.354	15.354	15.500	15.471	15.471	15.085	15.215	15.359	15.525	15.199	15.156	15.381	15.193	15.156	15.199	15.343	15.182
density functional	LSDA	11.197	15.301	15.301	16.045	15.532	15.532	16.037	15.996	15.996	15.418			15.712	15.864		15.979			15.864
	BLYP	10.596	14.438	14.438	15.204	14.776	14.776	15.364	15.222	15.222	14.653	15.287	15.310	14.945	15.143		15.308	15.257		15.143	15.301	15.248
	B1B95	11.449	15.249	15.249	15.849	15.123	15.243	15.623	15.575	15.575	15.087	15.526	15.575	15.425	15.274	15.275	15.425	15.321	15.295	15.274	15.578
	B3LYP	11.407	15.233	15.233	15.906	15.350	15.350	15.808	15.725	15.725	15.198	15.692	15.743	15.524	15.592	15.615	15.740	15.662	15.643	15.592	15.728	15.653
	B3LYPultrafine		15.234			15.349	15.349	15.806	15.724		15.197	15.692	15.742	15.522	15.592		15.739	15.662			15.728	15.653
	B3PW91	11.462	15.341	15.341	15.929	15.333	15.333	15.704	15.669	15.669	15.173	15.574	15.621	15.518	15.492		15.644	15.535		15.492	15.624	15.524
	mPW1PW91	11.561	15.389	15.422	15.985	15.327	15.327	15.694	15.643	15.670	15.187	15.572	15.627	15.514	15.463		15.656	15.535		15.463	15.635	15.526
	M06-2X	11.954	15.869	15.869	16.312	15.619	15.619	15.948	15.984	15.984	15.462	15.859	15.900	15.790	15.861		15.866	15.884			15.846	15.871
	PBEPBE	10.669	14.581	14.581	15.276	14.800	14.800	15.316	15.204	15.204	14.673	15.223	15.256	14.987	15.098	15.137	15.268	15.196	15.182	15.098	15.256	15.189
	PBEPBEultrafine		14.581			14.799	14.799	15.314	15.202		14.672	15.223	15.255	14.985	15.097		15.266	15.196			15.256	15.189
	PBE1PBE	11.441	15.329	15.329	15.909	15.276	15.276	15.646	15.589	15.589	15.111	15.502	15.567	15.465	15.423		15.583	15.476			15.563	15.467
	HSEh1PBE	11.437	15.330	15.330	15.910	15.283	15.283	15.658	15.605	15.605	15.117	15.515	15.587	15.468	15.441		15.591	15.491			15.571	15.482
	TPSSh	11.089	15.036	15.036	15.618	15.072	15.072	15.466	15.421	15.420	14.924	15.345	15.401	15.256	15.267	15.278	15.409	15.321	15.308		15.387	15.313
	wB97X-D	11.580	15.499	15.499	16.044	15.412	15.412	15.752	15.718	15.718	15.232	15.587	15.601	15.731	15.470	15.462	15.680	15.495	15.479		15.654	15.480
	B97D3	11.078	14.881	14.881	15.453	14.960	14.960	15.406	15.328	15.328	14.831	15.300	15.333	15.150	15.187	15.218	15.360	15.264	15.258		15.343	15.255
		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	daug-cc-pVDZ	daug-cc-pVTZ
Moller Plesset perturbation	MP2	10.349	13.947	13.947		14.785	14.785	15.172	15.034	15.035	14.886	15.349	15.100	14.861	15.214	15.362	15.257	15.348	15.419	15.214	15.247	15.340
	MP2=FULL	10.349	13.948	13.948		14.788	14.788	15.175	15.044	15.044	14.892	15.362	15.107	14.864	15.224	15.380	15.260	15.356	15.435	15.224	15.250	15.348
	MP3					15.394		15.807				15.730	15.544	15.483	15.638						15.702	15.732
	MP3=FULL		15.023	15.023	15.793	15.396	15.396	15.700	15.569	15.569	15.385	15.738	15.547	15.486	15.640		15.733	15.739			15.703	15.728
	MP4		14.556			15.067				15.232		15.484	15.262	15.143	15.328		15.501	15.488			15.487	15.481
	MP4=FULL		14.555			15.068				15.239		15.491		15.146	15.333		15.503	15.488			15.489	15.481
	B2PLYP	11.089	14.784	14.784	15.424	15.114	15.114	15.541	15.429	15.429	15.029	15.492	15.460	15.267	15.377		15.521	15.472			15.508	15.464
	B2PLYP=FULL	11.089	14.784	14.784	15.424	15.114	15.114	15.541	15.431	15.431	15.030	15.495	15.462	15.267	15.379		15.522	15.473			15.509	15.464
	B2PLYP=FULLultrafine	11.089	14.784	14.784	15.424	15.114	15.114	15.540	15.430	15.430	15.030	15.494	15.462	15.267	15.379		15.521	15.473			15.509	15.464
Configuration interaction	CID		15.185	15.185	15.858	15.398			15.568			15.663		15.513	15.590						15.658	15.662
	CISD		15.111	15.111	15.788	15.348			15.520			15.621		15.461	15.541						15.622	15.620
		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	daug-cc-pVDZ	daug-cc-pVTZ
Quadratic configuration interaction	QCISD		14.994	14.994	15.708	15.325	15.325	15.674	15.521	15.521	15.318	15.689	15.514	15.439	15.577		15.703	15.697		15.577	15.679	15.688
	QCISD(T)					15.227			15.424			15.625	15.422	15.331	15.490		15.634	15.634			15.614	15.625
	QCISD(T)=FULL					15.229		15.592				15.633		15.334	15.494	15.643	15.637	15.631	15.700		15.616	15.622
	QCISD(TQ)					15.204		15.562				15.615		15.314	15.485	15.624	15.611	15.622	15.682
	QCISD(TQ)=FULL					15.206		15.563						15.317	15.489	15.637		15.620	15.691
Coupled Cluster	CCD		15.093	15.093	15.809	15.401	15.401	15.713	15.593	15.593	15.398	15.748	15.574	15.518	15.656		15.748	15.759			15.722	15.749
	CCSD					15.347	15.347	15.683	15.544	15.544	15.339	15.703	15.532	15.463	15.598	15.720	15.714	15.713	15.768		15.689	15.703
	CCSD=FULL					15.348					15.342	15.711	15.536	15.466	15.601	15.733	15.716	15.709	15.778		15.691	15.700
	CCSD(T)					15.243	15.243	15.603	15.441	15.441	15.248	15.637	15.436	15.348	15.505	15.645	15.647	15.646	15.704	15.505	15.626	15.637
	CCSD(T)=FULL					15.244						15.645	15.440	15.351	15.508	15.657	15.649	15.643	15.712		15.628	15.634
		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	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	16.172	15.346	16.097	15.338	16.240	16.236			15.199
density functional	BLYP									15.220
	B1B95									15.469
	B3LYP	16.056	15.563	16.032	15.608	16.070	16.055			15.640
	B3LYPultrafine									15.640
	B3PW91									15.514
	mPW1PW91									15.516
	M06-2X									15.781
	PBEPBE									15.160
	PBEPBEultrafine									15.160
	PBE1PBE									15.456
	HSEh1PBE									15.476
	TPSSh									15.298
	wB97X-D	15.976	15.451	15.959	15.494	16.055	16.042			15.494
	B97D3									15.237
Moller Plesset perturbation	MP2		15.012		15.058					15.251
	MP2=FULL									15.258
	MP3									15.657
	MP3=FULL									15.660
	MP4									15.375
	MP4=FULL									15.379
	B2PLYP									15.426
	B2PLYP=FULL									15.427
	B2PLYP=FULLultrafine									15.427
Configuration interaction	CID									15.606
	CISD									15.560
Quadratic configuration interaction	QCISD									15.608
	QCISD(T)									15.526
	QCISD(T)=FULL									15.528
Coupled Cluster	CCD									15.678
	CCSD									15.626
	CCSD=FULL									15.629
	CCSD(T)									15.539
	CCSD(T)=FULL									15.542

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.