Nuclear Quantum Effects on Adsorption of H2 and Isotopologues on Metal Ions...

The nuclear quantum effects on the zero-point energy (ZPE), influencing adsorption of H$_2$ and isotopologues on metal ions, are examined using normal mode analysis of ab initio electronic structure results for complexes with 17 metal cations. To estimate for the anharmonicity, a nuclear wavepacket dynamics on the ground state electronic potential energy surfaces (PES) have been employed for complexes of Li$^+$ and Cu$^{+2}$ with H$_2$, D$_2$, HD. The dynamics analysis shows that incorporation of the PES anharmonicity changes the ZPE by up to 9\%. The lightest metallic nuclei, Li and Be, are found to be the most 'quantum'. The largest selectivity in adsorption is predicted for Cu, Ni and Co ions.