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Calculated Proton Affinity

15 11 04 06 09
Name Species   Species Name
Ethynyl radical C2H C2H2+ acetylene cation

Bonding changes

Bond type H-C changed by +1
Proton Affinities (kJ/mol)
Proton Affinities in kJ/mol
Methods with predefined basis sets
composite G1  
G2MP2  
G4 692

Proton Affinities in kJ/mol
Methods with standard basis sets
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z
hartree fock HF     747           743 789       789
ROHF     828                      
density functional BLYP     765                     777
B1B95                           782
B3LYP                 749 788       790
B3LYPultrafine                         788  
B3PW91                           788
mPW1PW91                           791
M06-2X   751 740                      
PBEPBE                   737       770
PBE1PBE     792                      
HSEh1PBE     793                      
TPSSh     767 759     773         793    
wB97X-D   770 804 797   794     794   797 798 797  
B97D3 744   834 820   826   824       803 763  
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z
Moller Plesset perturbation MP2     818   799       767 807       809
MP2=FULL                         808 810
MP3       847                    
MP3=FULL     830 833                    
MP4                       812    
B2PLYP     753                 780    
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z
Quadratic configuration interaction QCISD                           780
Coupled Cluster CCSD(T)                           773
3-21G 3-21G* 6-31G* 6-31+G** 6-311G* 6-311G** 6-31G(2df,p) 6-311+G(3df,2p) TZVP Def2TZVPP cc-pVDZ cc-pVTZ aug-cc-pVTZ cc-pV(T+d)Z
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.