Geometry Comparison
C2H- (Ethynyl anion)
distance is atom 1 (C) to atom 2 (C)
No experimental bond length available. Calculated bond lengths are shown.
Calculated bond length in Å
Methods with predefined basis sets
| semi-empirical |
PM6 |
1.216 |
| composite |
G2 |
1.228 |
| G3 |
1.228 |
| G3B3 |
1.250 |
| CBS-Q |
1.231 |
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) |
TZVP |
cc-pVDZ |
cc-pVTZ |
cc-pVQZ |
aug-cc-pVDZ |
aug-cc-pVTZ |
aug-cc-pVQZ |
| hartree fock |
HF |
1.195 |
1.233 |
1.233 |
1.239 |
1.228 |
1.228 |
1.233 |
1.225 |
1.224 |
1.222 |
1.223 |
1.234 |
1.222 |
1.221 |
1.237 |
1.224 |
1.223 |
| density functional |
LSDA |
1.240 |
1.258 |
1.258 |
1.264 |
1.255 |
1.255 |
1.255 |
1.245 |
1.244 |
1.248 |
|
1.258 |
1.241 |
1.239 |
1.257 |
1.241 |
1.240 |
| B1B95 |
1.231 |
1.253 |
1.253 |
1.258 |
1.249 |
1.249 |
1.250 |
1.242 |
1.241 |
1.242 |
|
1.253 |
1.238 |
1.236 |
1.253 |
1.239 |
1.238 |
| B3LYP |
1.234 |
1.253 |
1.253 |
1.259 |
1.250 |
1.250 |
1.252 |
1.242 |
1.241 |
1.243 |
1.240 |
1.253 |
1.238 |
1.237 |
1.254 |
1.239 |
1.238 |
| B3LYPultrafine |
|
|
|
|
1.250 |
|
|
|
|
|
|
|
|
|
|
|
|
| mPW1PW91 |
1.229 |
1.253 |
1.253 |
1.258 |
1.249 |
1.249 |
1.250 |
1.242 |
1.241 |
1.242 |
|
1.252 |
1.238 |
|
|
|
|
| PBEPBE |
1.247 |
1.268 |
1.268 |
1.272 |
1.263 |
1.263 |
1.263 |
1.255 |
1.255 |
1.257 |
|
1.266 |
1.251 |
1.249 |
|
|
1.250 |
| Moller Plesset perturbation |
MP2FC |
1.253 |
1.273 |
1.273 |
1.282 |
1.262 |
1.263 |
1.263 |
1.260 |
1.259 |
1.256 |
1.252 |
1.274 |
1.254 |
1.251 |
1.277 |
1.256 |
1.252 |
| MP2FU |
1.253 |
1.273 |
1.273 |
1.282 |
1.261 |
1.261 |
1.262 |
1.259 |
1.258 |
1.253 |
|
1.273 |
1.249 |
1.247 |
|
1.250 |
1.248 |
| MP3 |
|
|
|
|
1.248 |
|
|
|
|
|
|
|
|
|
|
|
|
| MP4 |
|
1.276 |
|
|
1.267 |
|
|
|
1.266 |
|
|
|
|
|
|
|
|
| Quadratic configuration interaction |
QCISD |
|
1.266 |
1.266 |
1.275 |
1.256 |
1.257 |
1.258 |
1.254 |
1.253 |
1.248 |
|
1.268 |
1.247 |
|
|
|
|
| Coupled Cluster |
CCD |
|
1.261 |
1.261 |
1.270 |
1.252 |
1.252 |
1.253 |
1.249 |
1.249 |
1.244 |
|
1.263 |
1.243 |
|
1.266 |
1.244 |
|
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 |
|
|
1.252 |
1.234 |
1.253 |
1.252 |
| density functional |
B3LYP |
1.301 |
1.291 |
1.274 |
1.257 |
1.275 |
1.275 |
| Moller Plesset perturbation |
MP2FC |
1.331 |
1.305 |
1.298 |
1.270 |
1.302 |
1.301 |
Values that are outliers may reflect different atom numbering for
different levels of theory.
Please use the error
report form to report problems.
