National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
NIST Standard Reference Database 101
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XIXIndex of properties
XXH-bond dimers
XXIOddities

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XVII.C.1. (III.D.6.)

Calculated Ionization Energy for P2 (Phosphorus diatomic)

Experimental Ionization Energy is 10.53 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.
Original data displayed. Press to display differences.
Differences displayed. Press to display original data.

Ionization Energies in eV
Methods with predefined basis sets
semi-empirical AM1  
PM3  
PM6  
composite G2 10.539
G3 10.546
G3B3 10.556
G4 10.806
CBS-Q 10.531

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) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
hartree fock HF 5.897 9.708 9.477 9.598 10.205 9.396 9.398 9.413 9.413 9.205 9.309 9.272 9.199 9.199 9.262 9.207 9.202
density functional LSDA 8.047 11.245 11.245 11.218 11.145 11.145 11.168 11.209 11.209 11.051   11.069 11.103   11.094 11.105  
SVWN   11.336         11.167       11.335            
BLYP 7.029 10.324 10.239 10.236 10.160 10.160 10.206 10.243 10.243 10.071   10.074 10.117        
B1B95 7.389 5.492 10.508 10.510 10.389 10.416 10.431 10.449 10.449 10.298   10.335 10.287   10.320 10.297  
B3LYP 7.234 10.584 10.468 10.482 10.384 10.384 10.414 10.445 10.445 10.278 10.366 10.295 10.313 10.316 10.333 10.325 10.321
B3LYPultrafine         10.384                     10.763  
B3PW91 7.400 10.734 10.599 10.597 10.490 10.490 10.497 10.520 10.520 10.365   10.412 10.388        
mPW1PW91 7.369 10.694 10.577 10.588 10.445 10.445 10.455 10.477 10.504 10.341   10.360 10.333        
M06-2X     10.477   10.477                        
PBEPBE 7.316 10.612 10.505 10.503 10.417 10.417 10.442 10.469 10.469 10.306   10.330 10.334        
PBE1PBE         10.839                        
HSEh1PBE   10.917         10.836           10.735        
TPSSh         10.456   10.465     10.327     10.352        
wB97X-D     10.612   10.480   10.489   10.504   10.434 10.489 10.368     10.372  
B97D3   10.527     10.308       10.357             10.239  
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
Moller Plesset perturbation MP2 6.665 10.272 10.399 10.256 10.339 10.339 10.360 10.382 10.382 10.533 10.359 10.367 10.578 10.672 10.494 10.633 10.701
MP2=FULL 6.657 10.269 10.402 10.255 10.342 10.342 10.362 10.382 10.382 10.554   10.373 10.586 10.674     10.706
MP3         10.015                        
MP3=FULL         10.013   10.027                    
MP4   10.141     10.173       10.223                
B2PLYP         10.339               10.361        
Configuration interaction CID   9.970 9.983 9.898 9.907     9.942                  
CISD   9.967 9.989 9.897 9.911     9.948                  
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ
Quadratic configuration interaction QCISD   10.055 10.121 10.004 10.049 10.049 10.064 10.088 10.088 10.216   10.054 10.251        
QCISD(T)         10.107             10.129 10.378   10.253 10.429  
Coupled Cluster CCD   10.056 10.105 10.000 10.035 10.035 10.049 10.070 10.070 10.205   10.041 10.242   10.146 10.287  
CCSD(T)         10.102             10.125 10.374   10.249 10.425  
CCSD(T)=FULL         10.102                        
STO-3G 3-21G 3-21G* 6-31G 6-31G* 6-31G** 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) TZVP cc-pVDZ cc-pVTZ cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ

Ionization Energies in eV
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 9.581 9.229 9.541 9.244 9.699 9.638
density functional B3LYP 10.428 10.242 10.369 10.213 10.508 10.528
Moller Plesset perturbation MP2 10.152 10.301 10.190 10.342 10.200 10.236
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.