Electronic Structure and Stability of Ordered Vacancy Phases of NbN
A recently reported metastable phase of NbN with a superconducting T c =16.4 K is characterized using full potential electronic structure methods. This new phase, which has Pm3m (cubic) symmetry, can be described as the B1 (rocksalt) structure with 25% ordered vacancies on each sublattice. We compare the equation of state and electronic spectrum of this Pm3m phase with its rocksalt counterpart [1] and with Nb 4 N 3 in the 14/mmm (tetragonal) phase, which allows the characterization of N vacancies without accompanying Nb vacancies. For Pm3m NbN, the calculated lattice constant is 5% smaller than reported and the energy is 1.00 eV/molecule higher than B1 NbN, suggesting that the newly reported phase is something other than a stoichiometric Pm3m phase of NbN. We report on the energy surface for tetragonal distortions of this phase, from which we evaluate its structural stability and obtain Poisson's ratio.
On the Numerical Calculation of the Density of States and Related Properties
A method is given for the numerical calculation of energy surface integrals within the Brillouin zone like density of states, conductivity, susceptibility, dielectric function etc. The Brillouin zone is divided into tetrahedrons in which the integrand is interpolated linearly. In this way the integration can be done analytically avoiding the histogram method. Several similar methods are discussed with regard to the quotient of accuracy and effort.
Code switching in Ahdaf Soueif's The Map of Love
This article examines the phenomenon of code switching in The Map of Love (1999) by the Egyptian—British writer Ahdaf Soueif. Though she chooses English as a medium for her creative expression, Soueif deploys Arabic in her narrative to represent different aspects of the linguistic and cultural norms of Egyptian society. The article's methodology is informed by Kachru's framework on contact literature and his categorization of the occurrence of literary code switching or bilingual creativity into different strategies that encompass cultural and linguistic processes. The results indicate the predominance in The Map of Love of the discourse strategies of employing lexical borrowing, culture-bound references and translational transfer. Finally, the article analyzes the functional motivation of code switching in the postcolonial context of the novel and how the use of certain creative strategies might enhance or diminish the narrative's effectiveness and readability.