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III.F.2.

Completed calculations for C4H2+ (diacetlyene cation)

Methods and basis sets for which an energy has been calculated. "e" indicates just an energy has been calculated. "o" indicates an optimized geometry. "v" indicates vibrational frequencies. "s" followed by a number indicates completed calculations for different states (for example s1ov). "c" followed by a number indicates completed calculations for different conformations (for example c2ov).
See the Calculated Energies page (section III.A.1) for more calculated properties.
Methods with predefined basis sets
semi-empirical AM1 c1o
PM3 c1o
composite G1 c1e
G2MP2 c1e
G2 c1e
G3 c1e
G3B3 c1e
G3MP2 c2e
G4 c1e c2e
CBS-Q c1e

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 c1o c1o c1o c1o c1o c2o c1o c1o c1o c1o c1o c1ov c1o c1o c1o c1o c1o c1o
ROHF c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o c1o c1o c1o c1o
density functional LSDA c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o c1o c1o c2o c1o  
SVWN   c1ov     c1ov   c1ov                    
BLYP c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o        
B1B95 c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o c1o c1o c1o c1o
B3LYP c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o c1ov c1o c1o c1o c1o c2o c1o c1o
B3LYPultrafine         c1o                     c1ov  
B3PW91 c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o        
mPW1PW91 c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o        
M06-2X         c1ov                        
PBEPBE c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o c1o      
PBE1PBE         c1ov                        
HSEh1PBE         c1ov                        
TPSSh         c1ov c2o   c1ov c2ov                    
Moller Plesset perturbation MP2 c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o c1ov c1o c1o c1o c1o c2o c1o c1o
MP2=FULL c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o c1o   c1o c1o
ROMP2 c1o c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o c1o c1o c1o c1o
MP3         c1o   c1o c2o                    
MP3=FULL         c1ov c2ov   c1ov c2ov                    
MP4   c1o     c1o       c1o                
B2PLYP         c1ov               c1ov        
Configuration interaction CID   c1o c1o c1o c1o     c1o                  
CISD   c1o c1o c1o c1o     c1o                  
Quadratic configuration interaction QCISD   c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o        
QCISD(T)         c1o             c1o c1o   c1o c1o  
Coupled Cluster CCD   c1o c1o c1o c1o c1o c1o c1o c1o c1o   c1o c1o   c1o c1o  
CCSD         c1o                        
CCSD(T)         c1o             c1o c1o   c1o c1o  
CCSD(T)=FULL         c1ov                        

Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF c1o c1o c1o c1o c1o c1o
density functional B3LYP c1o c1o c1o c1o c1o c1o
Moller Plesset perturbation MP2 c1o c1o c1o c1o c1o c1o

Single point energy calculations (select basis sets)
aug-cc-pVTZ
Moller Plesset perturbation MP2FC// MP2FC/6-31G* c1e
Coupled Cluster CCSD// MP2FC/6-31G* c1e
CCSD(T)// MP2FC/6-31G* c1e
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.