Non-Empirical Calculation of Electronic States of Impurity Polygon in Carbon Sheet: Pentagon

Abstract

Electronic states of the impurity pentagon in carbon sheet are calculated by the DV-Xα-LCAO method. The neighboring C atom of the central pentagon is negatively charged and other C atoms are almost neutral. The electric field for a negative (positive) sample bias induces the electron transfer from the tail-end (central pentagon) C atoms of carbon sheet to the central pentagon (tail-end) C atoms. Both the occupied orbitals near the HOMO for the negative sample bias and the unoccupied orbitals for the positive sample bias have high charge density around the central pentagon. This well reproduces the scanning tunneling microscopy images.