Abstract:
We resenttheresultsofcalculationsofsurfacerelaxations,rumplings,andchargedistributionforthe MgF2 (0 01)and(011)surfacesusing ab initio code Crystal-2003andthehybridexchange-correlation B3PW functional.Thesetwoneutralandpolarsurfacesshowverysmallrelaxationandnegligible increaseofcovalentcontributiontothechemicalbondingthusremainingconsiderablyionic.The calculatedbulkopticalbandgapisinagoodagreementwiththeexperimentalvalue,whereasoptical band gapforthepolar(011)surfaceisreducedby0.6eVcomparedwiththecalculatedbulkvalue,in contrasttothe(001)surfacegapwhichremainsveryclosetothebulk.
