On the Electronic Structure of Palladium—Hydrogen and Platinum—Hydrogen Systems

The interaction of hydrogen with palladium and platinum is studied on the basis of cluster calculations using the SW‐Xα method in a semirelativistic variant. Energy level spectra, density‐of‐states curves, and charge distributions are represented and discussed with respect to other theoretical and experimental investigations. The dominant role of covalent bond between hydrogen and palladium/platinum is illustrated. The results of the calculations show that for a heavy element as platinum relativistic effects can influence the bonding between atoms in a qualitative way. The less stability of the hydrogen—platinum system — compared with the PdH system — is explained as a relativistic effect.