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IV.D.1. (XII.C.1.)

Geometry Comparison

C2H2O2 (Ethanedial)


distance is atom 1 (C) to atom 3 (H)

Experimental bond length is 1.132  Å

original data displayed. press to display differences
differences displayed. press to display original data
Calculated bond length in Å
Methods with predefined basis sets
semi-empirical PM3 1.101
PM6 1.104
composite G2 1.091
G3 1.091
G3B3 1.109
CBS-Q 1.095
Calculated bond length in Å
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 cc-pVTZ aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 1.103 1.082 1.082 1.081 1.091 1.092 1.092 1.093 1.094 1.094 1.092 1.088 1.100 1.092 1.098 1.091
density functional LSDA 1.131 1.119 1.119 1.115 1.123 1.123 1.122 1.123 1.123 1.124     1.132 1.121 1.127  
SVWN   1.118     1.123   1.121                  
BLYP 1.139 1.114 1.114 1.112 1.120 1.120 1.117 1.119 1.118 1.120     1.129 1.115 1.123  
B1B95 1.124 1.101 1.101 1.099 1.106 1.107 1.106 1.107 1.107 1.108     1.116 1.104 1.110  
B3LYP 1.127 1.103 1.103 1.101 1.109 1.109 1.108 1.109   1.110 1.106 1.106 1.119 1.106 1.113 1.105
B3LYPultrafine         1.109   1.108                  
B3PW91   1.103 1.103 1.101 1.109 1.109 1.108 1.109   1.111     1.118 1.107 1.114  
mPW1PW91   1.101   1.099 1.107 1.107 1.106 1.107 1.107 1.109     1.116 1.105 1.112  
M06-2X         1.106                      
PBEPBE   1.116     1.121 1.121 1.119 1.121 1.120 1.122 1.118   1.130 1.118   1.117
PBEPBEultrafine         1.121                      
HSEh1PBE         1.108                      
Moller Plesset perturbation MP2FC   1.100 1.100 1.102 1.105 1.101 1.100 1.106 1.107 1.105   1.103 1.117 1.101 1.113  
MP2FU   1.100     1.105 1.100 1.099 1.106         1.116      
MP3         1.103                      
MP4         1.110                      
B2PLYP         1.106   1.105                  
Configuration interaction CID         1.098                      
CISD         1.098                      
Quadratic configuration interaction QCISD   1.104     1.107     1.108 1.107              
Coupled Cluster CCD         1.106                      
CCSD         1.106                      
CCSD(T)         1.109                      
Calculated bond length in Å
Methods with effective core potentials (select basis sets)
CEP-31G CEP-31G* CEP-121G CEP-121G* LANL2DZ SDD
hartree fock HF 1.088 1.096 1.086 1.094 1.083 1.083
density functional B1B95 1.110 1.116        
B3LYP 1.111 1.117 1.105 1.111 1.105 1.105
Moller Plesset perturbation MP2FC 1.114 1.114 1.106 1.106 1.107 1.107
Values that are outliers may reflect different atom numbering for different levels of theory.
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