Speaker: Xun-Wang Yan, Beijing Computational Science Research Center    

Abstract: By the first principles calculations based on the van der Waals density functional theory, we study the crystal structures and electronic properties of La-doped phenanthrene. Two stable atomic geometries of La1phenanthrene are obtained by relaxation of atomic positions from various initial structures. Structure-I is a metal with two energy bands cross the Fermi level. Structure-II displays the semiconducting state with an energy gap of 0.15 eV, and has an energy gain of 0.42 eV per unit cell in contrast to Structure-I. The most striking feature of La1phenanthrene is that La 5d electrons make a great contribution to the total density of state around Fermi energy level, which is obviously distinct from the potassium doped phenanthrene and picene. Our findings provide an important foundation for the understanding of superconductivity in La-doped phenanthrene. The cases for Ba-doped and Sr-doped phenanthrene are also discussed.

Date&Time: July 5, 2013 (Friday), 14:30 – 15:30
Location: 606 Conference Room