BUCKLED RECONSTRUCTION OF THE ALKALI-METAL (NA,K)-ADSORBED SI(111)-(3X1) SURFACES

The atomic and electronic structures of the alkali-metal (Na, K)-adsor bed Si(iii)-(3x1) surface are studied by the pseudopotential density-f unctional total-energy scheme for the structural models proposed to da te: the missing-top-layer (MTL), pi-bonded chain, and overlayer models including their variations. From the extensive investigation of them, we propose the MTL model as the ground-state structure of this system based both on the energetics and on the comparison of the calculated electronic structures with recent angle-resolved ultra-violet photoemi ssion data.