Table 1. CO2-Framework Interaction Energies (kJ/mol) in Fe2(dobdc) Computeda at a Fixed Geometry with Several DFT Functionals and QMC.
| functional | electronic binding energy (fixed Lee et al.33 geometry) | electronic binding energy (opt. geometry, Section 4.3) |
|---|---|---|
| PBE | –13.6 | –13.1 |
| optB88-vdW | –45.4 | –46.5 |
| optB86-vdW | –45.2 | –46.1 |
| vdW-DF2 | –38.1 | –38.1 |
| rev-vdW-DF2 | –36.4 | –37.3 |
| PBE-D2 | –33.5 | –33.9 |
| PBE-D3 | –34.7 | –34.5 |
| PBE-D3 BJ | –35.3 | –35.3 |
| QMC | –44.0(2.0) to –41.0(2.0) |
a
DFT binding energies where the position of CO2 has been optimized are also reported for comparison. The stochastic error bars on the QMC binding energies are given in parentheses, and the two values correspond to the binding energy obtained using the approach of Chiesa et al.73 and the MPC interaction70 to correct for finite size errors, respectively.