Home  About us  Contact
 

Muffin-tin Orbital (muffin-tin + orbital)

Distribution by Scientific Domains
Chemistry50%

Terms modified by Muffin-tin Orbital

  • muffin-tin orbital method
    		•

    Selected Abstracts

    Electronic structure studies of DyNi4Cu

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 1 2006
    M. Pugaczowa-Michalska
    Abstract Electronic structure of the DyNi4Cu compound, crystallising in the hexagonal CaCu5 -type of structure has been studied using the XPS method as well as the self-consistent spin-polarised TB-LMTO (tigh-binding linear muffin-tin orbital) method. Our calculations show that DyNi4Cu is ferromagnetically ordered at 0 K. The analysis of the valence band shape in vicinity of the Fermi level shows that this part of the spectrum comes mainly from 3d electrons of Ni and Cu atoms. The features of the experimental XPS valence band spectra near the Fermi level are reproduced in our calculations. Peaks below ,7.5 eV are connected with the contribution of the f -electrons of Dy. The obtained peak positions in the valence band are in good agreement with the binding energies of metallic dysprosium, copper and nickel. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Calculated high pressure crystal structure transformations for phosphorus

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003
    Rajeev Ahuja
    Abstract In this paper we have studied the structural stability of the sp bonded element, P, by means of the first principles calculations. The theoretical calculations made use of a full potential linear muffin-tin orbital (FPLMTO) method adopting the local density approximation to the density functional theory. We reproduce the observed crystallographic phase stability of P as a function of compression. Our results confirm the recent experimental finding of Akahama et al. We have also proposed a new structure for an experimentally reported unidentified intermediate phase in between simple cubic and simple hexagonal phase. This new structure is similar to what has been observed for Si. We have explained the stability of different phases under pressure using our calculated density of states (DOS). [source]

    Features of the electron density in magnesium diboride: reconstruction from X-ray diffraction data and comparison with TB-LMTO and FPLO calculations

    ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2003
    S. Lee
    Features of the electron density in MgB2 reconstructed from room-temperature single-crystal X-ray diffraction intensities using a multipole model are considered. Topological analysis of the total electron density has been applied to characterize the atomic interactions in magnesium diboride. The shared-type B,B interaction in the B-atom layer reveals that both , and , components of the bonding are strong. A closed-shell-type weak B,B , interaction along the c axis of the unit cell has also been found. The Mg,B closed-shell interaction exhibits a bond path that is significantly curved towards the vertical Mg-atom chain ([110] direction). The latter two facts reflect two sorts of bonding interactions along the [001] direction. Integration of the electron density over the zero-flux atomic basins reveals a charge transfer of ,1.4,(1) electrons from the Mg atoms to the B-atom network. The calculated electric-field gradients at nuclear positions are in good agreement with experimental NMR values. The anharmonic displacement of the B atoms is also discussed. Calculations of the electron density by tight-binding linear muffin-tin orbital (TB-LMTO) and full-potential non-orthogonal local orbital (FPLO) methods confirm the results of the reconstruction from X-ray diffraction; for example, a charge transfer of 1.5 and 1.6 electrons, respectively, was found. [source]

    Muffin-Tin Orbital Wannier-Like Functions for Insulators and Metals

    CHEMPHYSCHEM, Issue 9 2005
    Eva Zurek
    Abstract Herein, we outline a method that is able to generate truly minimal basis sets that accurately describe either a group of bands, a band, or even just the occupied part of a band. These basis sets are the so-called NMTOs, muffin-tin orbitals of order N. For an isolated set of bands, symmetrical orthonormalization of the NMTOs yields a set of Wannier functions that are atom-centered and localized by construction. They are not necessarily maximally localized, but may be transformed into those Wannier functions. For bands that overlap others, Wannier-like functions can be generated. It is shown that NMTOs give a chemical understanding of an extended system. In particular, orbitals for the , and , bands in an insulator, boron nitride, and a semimetal, graphite, will be considered. In addition, we illustrate that it is possible to obtain Wannier-like functions for only the occupied states in a metallic system by generating NMTOs for cesium. Finally, we visualize the pressure-induced s,d transition. [source]