Berlin 2005 – scientific programme

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M: Metallphysik

M 32: Poster TU B (Symposium Tomographic Methods in Materials Research M-32.32-55)

M 32.7: Poster

Monday, March 7, 2005, 14:30–16:30, Poster TU B

Structure and Chemical Bonding in High Pressure Phases of the Heavy Pnictides, Sb and Bi — •Alim Ormeci and Helge Rosner — MPI CPfS Dresden, Germany

In recent years the high-pressure structures of Sb and Bi have been determined by very accurate experimental techniques. The sequence of the observed structural phase transitions are, in general, reproduced correctly by first-principles electronic structure methods. In this work we combine first-principles total-energy calculations with the topological analysis of the electron localization function (ELF) in order to study how crystal structure and bonding properties change as pressure is applied. Total-energy calculations are carried out by using the (i) full-potential linear muffin-tin-orbital method (FP-LMTO), and (ii) full-potential local orbital (FPLO) method. The ELF is calculated by using the FPLO method.

A particular issue is the importance of the relativistic effects to the electronic structure and to the crystal structure in Bi. This issue is investigated systematically by performing calculations based on the following approaches: (i) scalar relativistic Hamiltonian, (ii) spin-orbit coupling treated variationally, (iii) full Dirac Hamiltonian in a four-component implementation.