Periodic DFT+U investigation of the bulk and surface properties of marcasite (FeS₂)

Abstract

Marcasite FeS2 and its surfaces properties have been investigated by Hubbard-corrected DensityFunctional Theory (DFT+U) calculations. The calculated structural parameters, interatomic bond distances, elastic constants and electronic properties of the bulk mineral were determined and compared with earlier theoretical reports and experimental data where available. We have also investigated the relative stability, interlayer spacing relaxations, work function, and electronic structures of the {010}, {101}, {110} and {130} surfaces under dehydrated and hydrated conditions. Using the calculated surface energies, we have derived the equilibrium crystal shape of marcasite from a Wulff construction. The {101} and {010} surfaces dominate the marcasite crystallite surface area under both dehydrated and hydrated conditions, in agreement with their relative stabilities compared to the other surfaces. The simulated scanning tunneling microscopy (STM) images of the {101} and {010} facets are also presented, for comparison with future experiments.

Surfaces, Interfaces and Crystal Growth of Marcasite FeS2

“…The orthorhombic system has 9 independent values for elastic constants and 3 for dielectric constants which reflects anisotropic properties. Elastic properties from classical simulations are in very good agreement with DFT/PBE+U calculations 12,15 and experiment (bulk modulus B of 146. The mineral is then easiest to distort upon a shear stress rather than compression.…”

“…Few theoretical studies have reported surface energies of marcasite. The main results from DFT studies 15,35 are in Table 3 for comparative purpose. The order of surface energies after relaxation, calculated with force field, is as follows: < (010) < (001) < (111) < (121) < (102) < (103) < (031) < (305) < (100) < (130) < (211) < (011) < (201) < (120) < (021) < (210) < (110)…”

“…Most of the properties have been investigated with DFT (Density Functional Theory) methods (such as calculating band gap, elastic properties, thermoelectric properties [14][15][16] ). Marcasite has been frequently disregarded as it was believed that its band gap was low (E g =0.34eV 17 ), incompatible for photovoltaic applications which has been first dismantled by first-principle simulations 14 and then by diffuse reflectance.…”

Uncovering the origin of enhanced field emission properties of rGO–MnO2heterostructures: a synergistic experimental and computational investigation

“…Dipole correction perpendicular to all surfaces was accounted for, which ensured that there is no net dipole perpendicular to the surfaces that may affect the potential in the vacuum level. [51][52][53] 3. Results and discussions…”

First–Principles Investigation of the Structural, Elastic, Electronic, and Optical Properties of α– and β–SrZrS3: Implications for Photovoltaic Applications

“…The elastic properties of materials give the data necessary in understanding the bonding property between adjacent atomic planes, stiffness, bonding anisotropic and structural stability of the material [35,36]. Shown in Table 2 are the calculated single crystal elastic constants of the αand β-SrZrS 3 materials, all of which satisfy the Born's mechanical stability criteria for orthorhombic structures [37], indicating that both materials are mechanically stable under ambient conditions.…”