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Calculated Ionization Energy for K (Potassium atom)

20 09 09 14 00
Experimental Ionization Energy is 4.34066 ± 0.00001 eV
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 PM3  
PM6  
composite G1 4.269
G2MP2 4.279
G2 4.271
G3B3 4.307
G3MP2 4.324
G4 4.317

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
hartree fock HF 1.862 3.983 3.984 4.010 4.010 4.010 4.010 4.003 4.003 4.010   4.009  
ROHF   3.982 3.983 4.008 4.008 4.008 4.008 4.001 4.001        
density functional LSDA 3.463 4.824 4.834 4.887 4.917 4.917 4.917 4.915 4.915 4.917      
BLYP 2.871 4.382 4.383 4.406 4.432 4.432 4.433 4.426 4.426 4.433      
B1B95 2.673   4.218 4.260 4.288 4.266 4.266 4.255 4.255 4.271      
B3LYP 2.895 4.452 4.453 4.480 4.502 4.502 4.502 4.494 4.494 4.502   4.489  
B3LYPultrafine         4.502                
B3PW91 2.736 4.318 4.320 4.364 4.373 4.373 4.373 4.365 4.365 4.377      
mPW1PW91 2.675 4.322 4.324 4.353 4.360 4.360 4.360 4.351 4.351 4.365      
M06-2X     4.065                    
PBEPBE 2.808 4.407 4.408 4.432 4.446 4.446 4.446 4.439 4.439 4.450      
PBE1PBE         4.377                
TPSSh         4.240   4.240     4.246      
wB97X-D     4.040   4.122   4.122   4.114     4.107 4.129
B97D3   3.941     3.970   3.970   3.962   3.963    
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
Moller Plesset perturbation MP2 1.862 3.983 3.984 4.015 4.124 4.124 4.126 4.234 4.234 4.157   4.009  
MP2=FULL 1.896 3.989 4.020 4.015 4.124 4.124 4.126 4.237 4.237 4.157      
ROMP2 1.852   3.983 4.030 4.566 4.566 4.570 8.554 8.554 6.780      
MP3             4.140            
MP3=FULL         4.140   4.142            
MP4   3.983     4.146       4.243        
Configuration interaction CID   3.983 3.984 4.017 4.141     4.198          
CISD   3.983 3.984 4.017 4.144     4.204          
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
Quadratic configuration interaction QCISD   3.983 3.984 4.017 4.147 4.147 4.149 4.237 4.237 4.161      
QCISD(T)         4.148                
Coupled Cluster CCD   3.983 3.984 4.017 4.143 4.143 4.146 4.224 4.224 4.158      
CCSD         4.146                
CCSD(T)         4.148                
CCSD(T)=FULL         4.148                
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

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         3.985 3.996     4.009
density functional B3LYP         4.445 4.497     4.487
PBEPBE                 4.434
Moller Plesset perturbation MP2         3.990 4.030     4.009
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.