We have investigated several ways of introducing a solvated proton into a DFT calculation in order to mimic an electrochemical interface: an extra hydrogen introduced into a metal bilayer, a Zundel and an Eigen ion. In all these cases the charge on the supposed proton is substantially less than a unit positive charge. In contrast, when the electrode is represented as a cluster, the charge on Zundel ion is indeed plus one. However, the distribution of the compensating charge on the cluster is quite different from that on a plane metal surface.
Bibliographical noteFunding Information:
Financial support by the Deutsche Forschungsgemeinschaft ( Schm 344/34-1,2 , SCHM 344/42-1,2 , Sa 1770/1-1,2 , and FOR 1376 ), by RFBR ( 11-03-01186-a ), and by CONICET ( PIP 112-201001-00411 ), and by the international cooperation between CONICET and DFG, are gratefully acknowledged. We thank CONICET, Argentina, for continued support. A generous grant of computing time from the Baden-Württemberg grid is gratefully acknowledged.
- Eigen ion
- Water bilayer
- Zundel ion