return to home page

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

Geometry Comparison

CH3NC (methyl isocyanide)


distance is atom 2 (N) to atom 3 (C)

Experimental bond length is 1.166  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 AM1 1.181
PM3 1.181
PM6 1.167
composite G3 1.153
CBS-Q 1.155

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 cc-pVQZ aug-cc-pVDZ aug-cc-pVTZ
hartree fock HF 1.171 1.160 1.160 1.164 1.153 1.153 1.152 1.148 1.148 1.148 1.144 1.145 1.155 1.145 1.126 1.154 1.144
density functional LSDA 1.218 1.186 1.186 1.191 1.182 1.182 1.179 1.173 1.173 1.176     1.184 1.169   1.180  
SVWN   1.186     1.182   1.179                    
BLYP 1.228 1.195 1.195 1.199 1.190 1.190 1.187 1.181 1.181 1.184     1.191 1.177      
B1B95 1.208 1.180 1.180 1.185 1.176 1.176 1.173 1.169 1.169       1.177 1.165      
B3LYP 1.211 1.182 1.182 1.187 1.177 1.177 1.175 1.169 1.169 1.171   1.166 1.179 1.166   1.175 1.165
B3LYPultrafine         1.177                        
B3PW91 1.210 1.183 1.183 1.187 1.177 1.177 1.175 1.170 1.170 1.172     1.179 1.166      
mPW1PW91 1.206 1.180 1.180 1.184 1.175 1.175 1.173 1.168 1.168 1.169     1.176 1.164      
M06-2X         1.173                        
PBEPBE 1.225 1.195 1.195 1.199 1.190 1.190 1.187 1.182 1.182 1.184     1.191 1.178     1.177
HSEh1PBE         1.175                        
Moller Plesset perturbation MP2FC 1.221 1.199 1.199 1.206 1.189 1.189 1.188 1.183 1.183 1.182   1.178 1.195 1.179   1.194  
MP2FU 1.221 1.199 1.199 1.205 1.188 1.188 1.186 1.182 1.182 1.177     1.194 1.175      
MP3         1.174                        
MP4   1.206     1.195                        
B2PLYP         1.182   1.180                    
Configuration interaction CID   1.178 1.178 1.184 1.170     1.163                  
CISD   1.181 1.181 1.186 1.171     1.165                  
Quadratic configuration interaction QCISD 1.214 1.192 1.192 1.198 1.183 1.183 1.181 1.176 1.176 1.174     1.187 1.170      
QCISD(T)         1.188   1.186   1.183                
Coupled Cluster CCD 1.206 1.186 1.186 1.192 1.178 1.178 1.176 1.172 1.172 1.170     1.182 1.166      
CCSD(T)         1.187   1.185   1.182                

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 1.177 1.167 1.171 1.156 1.168 1.168
density functional B1B95 1.201 1.192        
B3LYP 1.204 1.193 1.197 1.182 1.193 1.193
Moller Plesset perturbation MP2FC 1.228 1.205 1.216 1.195 1.214 1.214
Values that are outliers may reflect different atom numbering for different levels of theory.
Please use the error report form to report problems.