On the origin of the C induced $p4g$ reconstruction of Ni(001)

TL;DR

This study uses first principles calculations to investigate how carbon adsorption induces a $p4g$ reconstruction on Ni(001), revealing electronic and structural mechanisms behind the phenomenon.

Contribution

It provides detailed insights into the reconstruction mechanism, including energetics and electronic charge redistribution, which were not previously well understood.

Findings

Reconstruction path and energetics are characterized.

Significant reduction in local electronic charge on C upon reconstruction.

Formation of covalent bonds between C and second layer Ni atoms.

Abstract

First principles calculations of the geometric and electronic structures have been performed for two coverages (0.25 ML and 0.5 ML) of C on Ni(001) to understand the mechanism of the Ni(001) reconstruction induced by carbon adsorption. The calculated structural behavior of the system is in a good agreement with experimental observations. The calculated path and energetics of the $c(2\times 2)$ -- $p4g$ reconstruction in C$_{0.5}$/Ni(001) is provided. A dramatic reduction of the local electronic charge on adsorbed carbon is found to occur upon the reconstruction that decreases the electron-electron repulsion on C site. This effect together with the formation of covalent bonds between C and the second layer Ni atoms, leads to reconstruction of Ni(001).