Geometry Comparison
H2- (hydrogen diatomic anion)
distance is atom 1 (H) to atom 2 (H)
No experimental bond length available. Calculated bond lengths are shown.
Calculated bond length in Å
Methods with predefined basis sets
| semi-empirical |
AM1 |
0.979 |
| PM3 |
0.943 |
| PM6 |
1.023 |
| composite |
G2 |
1.547 |
| G3 |
1.547 |
| G3B3 |
1.660 |
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 |
1.579 |
1.562 |
1.562 |
1.547 |
1.547 |
1.528 |
1.528 |
1.582 |
1.374 |
1.528 |
1.379 |
1.488 |
1.382 |
0.941 |
0.759 |
0.744 |
0.742 |
| ROHF |
|
|
|
|
1.479 |
|
|
|
|
|
|
|
|
|
|
|
|
| density functional |
LSDA |
1.776 |
1.686 |
1.686 |
1.591 |
1.591 |
1.597 |
1.597 |
1.342 |
1.194 |
1.597 |
|
1.435 |
1.188 |
|
0.806 |
|
|
| SVWN |
|
1.686 |
|
|
1.592 |
|
1.597 |
|
|
|
|
|
|
|
|
|
|
| BLYP |
1.858 |
2.474 |
2.474 |
|
|
1.904 |
1.904 |
1.516 |
1.318 |
1.904 |
|
1.646 |
1.312 |
|
|
|
|
| B1B95 |
|
1.762 |
1.762 |
1.659 |
1.659 |
1.654 |
1.654 |
1.476 |
1.283 |
1.654 |
|
1.537 |
1.278 |
0.951 |
|
0.754 |
0.750 |
| B3LYP |
1.762 |
1.769 |
1.769 |
1.660 |
1.660 |
1.651 |
1.651 |
1.458 |
1.253 |
1.651 |
1.258 |
1.525 |
1.249 |
0.959 |
0.778 |
0.757 |
0.753 |
| B3LYPultrafine |
|
|
|
|
1.660 |
|
|
|
|
|
|
|
|
|
|
|
|
| B3PW91 |
1.757 |
1.654 |
1.654 |
1.576 |
1.576 |
1.573 |
1.573 |
1.298 |
1.128 |
1.573 |
|
1.419 |
1.132 |
|
|
|
|
| mPW1PW91 |
1.734 |
1.610 |
1.610 |
1.548 |
1.548 |
1.543 |
1.543 |
1.274 |
1.117 |
1.543 |
|
1.395 |
1.123 |
|
|
|
|
| M06-2X |
|
|
|
|
1.569 |
|
|
|
|
|
|
|
|
|
|
|
|
| PBEPBE |
1.838 |
1.807 |
1.807 |
1.643 |
1.643 |
1.640 |
1.640 |
1.323 |
1.141 |
1.640 |
|
1.452 |
1.143 |
0.954 |
|
0.766 |
0.762 |
| HSEh1PBE |
|
|
|
|
1.556 |
|
|
|
|
|
|
|
|
|
|
|
|
| Moller Plesset perturbation |
MP2FC |
1.579 |
1.579 |
1.579 |
1.556 |
1.556 |
1.440 |
1.440 |
1.423 |
1.087 |
1.440 |
1.083 |
1.333 |
1.123 |
0.949 |
0.772 |
0.751 |
0.747 |
| MP2FU |
1.579 |
1.579 |
1.579 |
1.556 |
1.556 |
1.440 |
1.440 |
1.423 |
1.087 |
1.440 |
|
1.333 |
1.123 |
0.949 |
0.772 |
0.751 |
0.747 |
| MP3 |
|
|
|
|
1.563 |
|
|
|
|
|
|
|
|
|
|
|
|
| MP4 |
|
1.591 |
|
|
1.568 |
|
|
|
1.093 |
|
|
|
1.157 |
|
|
|
|
| B2PLYP |
|
|
|
|
1.592 |
|
1.547 |
|
|
|
|
|
|
|
|
|
|
| Configuration interaction |
CID |
|
1.592 |
1.592 |
1.568 |
1.568 |
|
|
1.501 |
|
|
|
|
|
|
|
|
|
| CISD |
|
1.596 |
1.596 |
1.574 |
1.574 |
|
|
1.555 |
|
|
|
|
|
|
|
|
|
| Quadratic configuration interaction |
QCISD |
|
1.596 |
1.596 |
1.574 |
1.574 |
1.433 |
1.433 |
1.555 |
1.102 |
1.433 |
|
1.333 |
1.177 |
|
|
0.758 |
|
| QCISD(T) |
|
|
|
|
1.575 |
1.433 |
1.433 |
1.555 |
|
|
|
1.333 |
1.175 |
|
|
0.758 |
|
| Coupled Cluster |
CCD |
|
1.592 |
1.592 |
1.568 |
1.568 |
1.428 |
1.428 |
1.501 |
1.099 |
1.428 |
|
1.320 |
1.169 |
|
|
0.757 |
|
| CCSD |
|
|
|
|
1.574 |
1.433 |
|
1.553 |
|
|
|
|
|
|
|
|
|
| CCSD(T) |
|
|
|
|
1.575 |
1.433 |
1.433 |
1.554 |
|
|
|
1.333 |
1.175 |
0.977 |
|
0.758 |
0.754 |
| CCSD(T)=FULL |
|
|
|
|
1.575 |
|
|
|
|
|
|
|
|
0.977 |
|
|
0.754 |
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 |
1.550 |
1.550 |
1.582 |
1.582 |
1.550 |
1.550 |
| density functional |
B3LYP |
1.735 |
1.735 |
1.458 |
1.458 |
1.735 |
1.735 |
| Moller Plesset perturbation |
MP2FC |
1.566 |
1.566 |
1.423 |
1.423 |
1.566 |
1.566 |
Values that are outliers may reflect different atom numbering for
different levels of theory.
Please use the error
report form to report problems.
