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Transition State Energies for H + H2 = H2 + H


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Energies in kJ/mol relative to reactant
Methods with predefined basis sets
semi-empirical AM1 -12.8
PM3 -85.3

Energies in kJ/mol relative to reactant
Methods with standard basis sets
3-21G 6-31G* 6-31+G** 6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 71.1 75.0 74.8 73.9 70.6 73.6 70.1  
ROHF   5470.7            
density functional B3LYP 15.0 18.4 17.2   13.2 17.8 13.2  
mPW1PW91 22.3 26.5 24.8   20.6 24.5    
3-21G 6-31G* 6-31+G** 6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
Moller Plesset perturbation MP2 69.7 71.9 64.0 57.6 55.6 55.3 52.9 31.5
3-21G 6-31G* 6-31+G** 6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
Quadratic configuration interaction QCISD 60.5 62.3 54.7   43.9 43.0    
Coupled Cluster CCD 64.1 65.8 58.5 48.8 47.9 47.0 44.1 46.1
CCSD 60.5 62.3 54.8 44.9 43.9 43.1 40.1 42.1
CCSD(T) 60.3 62.0 54.1 43.9 43.1 41.9 39.1 40.9
3-21G 6-31G* 6-31+G** 6-311+G(3df,2p) cc-pVDZ cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary Predefined means the basis set used is determined by the method.