Intramolecular relaxation observed in the surface of the quasi-one-dimensional organic conductor (formula presented)

Abstract

In addition to the intermolecular symmetry breaking which is generally observed during the surface relaxation/reconstruction of atomic crystals, intramolecular relaxation is expected to exist in the case of molecular crystals, which was confirmed on the surface of (formula presented) [BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene] by using scanning tunneling microscopy (STM). Two types of molecular images obtained by STM were comprehensively explained by the spatial distributions of the highest-occupied molecular orbital calculated for the two types of the molecular structures. One is the structure appearing in the crystal that is derived from the x-ray diffraction measurement, which was used in the previous calculations to reproduce the STM images. The other is the relaxed molecular structure calculated by optimization of the molecular structure. © 2001 The American Physical Society.