Systematic Approach To Calculate the Band Gap Energy of a Disordered Compound with a Low Symmetry and Large Cell Size via Density Functional Theory.

ABSTRACT: An ab initio calculation based on density functional theory (DFT) was used to verify the disordered structure of a novel oxynitride phosphor host, La_4-x Ca _x Si₁₂O_3+x N_18-x , with a large unit cell (74 atoms), low level of symmetry (C2), and large band gap (4.45 eV). Several Wyckoff sites in the La_4-x Ca _x Si₁₂O_3+x N_18-x structure were randomly shared by La/Ca and O/N ions. This type of structure is referred to as either partially occupied or disordered. The adoption of a supercell that is sufficiently large along with an infinite variety of ensemble configurations to simulate such a random distribution in a partially o

SUBMITTER: Park WB 

PROVIDER: S-EPMC6640787 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature