First-principles study of 6H-AlN under various pressure conditions

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...

Optical properties of calcium under pressure from first-principles calculations

Ion Errea,1,2,3,* Bruno Rousseau,2,3,† Asier Eiguren,1,2 and Aitor Bergara1,2,3 1Materia Kondentsatuaren Fisika Saila, Zientzia eta Teknologia Fakultatea, Euskal Herriko Unibertsitatea UPV/EHU, 644 Postakutxatila, 48080 Bilbao, Basque Country, Spain 2Donostia International Physics Center (DIPC), Manuel de Lardizabal Pasealekua 4, 20018 Donostia, Basque Country, Spain 3Centro de Fı́sica de Materi...

Phases of vanadium under pressure investigated from first principles.

The existence and stability under pressure of three phases of vanadium are calculated from first principles. The phases are one body-centered cubic (bcc) and two rhombohedral phases (rh(u) and rh(l)), which have greater and lower α values than the primitive bcc rhombohedral cell. The bcc phase is shown in two ways to become unstable at 0.65 Mbar, in agreement with an observed phase transition, ...

First-principles thermoelasticity of bcc iron under pressure

We investigate the elastic and isotropic aggregate properties of ferromagnetic bcc iron as a function of temperature and pressure by computing the Helmholtz free energies for the volume-conserving strained structures using the first-principles linear response linear-muffin-tin-orbital method and the generalized-gradient approximation. We include the electronic excitation contributions to the fr...