First-Principles Study on High-Pressure Synthesis of Hetero-Diamond BC2N.

A First Principles Study of Nickel Defects in Synthetic Diamond

Spin-polarised local density functional cluster calculations are carried out on iso-(S=1/2) lies at the T d site. Ni ? s (S=3/2) is shown to be stable and remains on-site in agreement with experimental results. Donor-acceptor complexes of Ni, namely Ni + i-B ? s , Ni ? s-N + s and Ni + s-B ? s are stable trigonal defects which have a number of gap levels. Optical transitions are expected betwee...

Electronic Structure of B-doped Diamond: A First-principles Study

Electronic structure of B-doped diamond is studied based on first-principles calculations with supercell models for substitutional and interstitial doping at 1.5–3.1 at.% B concentrations. Substitutional doping induces holes around the valence-band maximum in a rigid-band fashion. The nearest neighbor C site to B shows a large energy shift of 1s core state, which may explain reasonably experime...

First Principles Study of Tetracene under Pressure

First-principles study of CaFe2As2 under pressure

We perform first-principles calculations on CaFe2As2 under hydrostatic pressure. Our total-energy calculations show that though the striped antiferromagnetic (AFM) orthorhombic (OR) phase is favored at P = 0, a nonmagnetic collapsed tetragonal (cT) phase with diminished c parameter is favored for P > 0.36 GPa, in agreement with experiments. Rather than a mechanical instability, this is an entha...

effects of first language on second language writing-a preliminary contrastive rhetoric study of farsi and english

to explore the idea the investingation proposed, aimed at finding whether the performances of the population of iranians students studying english in an efl context are consistent in l1 and l2 writing taks and whether there is a cross-linguistic transfer in this respect. in this regard the subjects were instructed to write four compositions-two in english and two in farsi-which consisted of an ...