The biggest challenge in the commercial application of electrochemical reduction of water through the hydrogen evolution reaction (HER) is hampered due to the scarcity of inexpensive and efficient catalysts. Herein, we propose a metal-free biphenylene nanosheet, a recently proposed two- dimensional (2D) carbon allotrope [Science 372.6544 (2021)], as an excellent HER electrocatalyst. The...
Computation of lattice dynamics including anharmonic effects at a given temperature is critically important for describing phonon transport in extended solids, accurately. I will showcase with few examples, how temperature dependent effective potential (TDEP) method [1] in combination with ab-initio molecular dynamics (AIMD) simulations aid to describe the anharmonic lattice dynamics,...
The catalytic activities of several different heterogeneous catalysts, ranging from planar extended surfaces to clusters and particles with different shapes, sizes or compositions, have been experimentally determined for a long time. However, a fully understanding of the catalytic mechanisms is a defiant task because of the large number of variables that determine the performance of the...
In this talk I will discuss the parallelisation strategy VASP employs to distribute its work and data, and the ways a user may influence these to optimise the performance of VASP on high-performance computing (HPC) resources, be it CPU-only or GPU-accelerated hardware. The main focus will be on aspects of the parallelisation using MPI, but I will briefly touch upon the use of MPI + OpenMP as well.
Utilizing the density functional theory (DFT), a detailed investigation of hydrogen adsorption on pristine and alkali metal-decorated boron nitride and carbon nanostructures was conducted. Although the average adsorption energy is below the US-DOE threshold, the hydrogen adsorption on pure boron nitride system is still promising in terms of theoretical storage capacity. In the case of bilayer...
Electrides are rare ionic compounds in which an electron does not occupy an atomic orbital but ex-ists as a free electron in a cavity of the crystal lattice. This electron behaves differently to those occu-pying the valence state of standard materials, making electrides desirable as electron emitters,[1] non-linear optical switches,[2] superconductors,[3] battery anodes,[4] and catalysts for...
Several intermetallic phases are important in the design of Nickelbase superalloys: The $\gamma'$-phase (Ni3Al) and $\gamma''$-phase (Ni3Nb) provide strengthening whereas the $\delta$-phase (Ni3Nb) and $\eta$-phase (Ni3Ti) are important in ensuring a fine-grained structure in wrought alloys, but may also be detrimental because they may embrittle the alloy.
The solution energies of all...
Mn$_3$Si$_2$Te$_6$ single crystals were first synthesized in 1985 [1], however, few studies were carried out on this compound since. It was only recently that the attention has shifted to them, mainly through the comparisons with quasi-two-dimensional materials, specifically CrSiTe$_3$. Layered magnetic van der Waals materials have lately received widespread attention due to their relevnce for...
Photovoltaic (PV) installations have recently reached the terawatt level and this is almost entirely due to the success of silicon-based solar cell technologies. Silicon PV is low-cost and cell efficiencies are unrivalled by other mass-market single-junction technologies. Improvements in silicon cells will have a real-world impact on climate change mitigation and improving energy supply...
Understanding thermal transport is of fundamental importance in several technological applications, like transistors, optoelectronics, photovoltaics, and thermoelectrics. Materials with an intrinsic low lattice thermal conductivity (kl) provides a pathway for discovering high zT materials without degrading its charge transport. Lattice expansion is one of the strategies to achieve low kl...
We will consider the case of cerium dioxide, an important material in water gas shift reactions, three-way catalysis, soot oxidation, and enzyme mimetic activity (nanozymes). In such catalytic applications, the performance of the catalyst is dependent on the morphology of the nanoparticle. Control of size and morphology of nanoparticles is therefore key for the design of energy and catalytic...
The purpose of the present Density Functional Theory (DFT) study is an investigation the role of mixing level on the dielectric/ electronic properties by doping the PbTiO3 (PTO) to obtain lead Zirconium Titanate (PZT). The starting composite was prepared for the PZT ceramic which is used in numerous applications including actuators. Here, we focus on understanding the effect of Ti substitution...
Non-Abelian braiding of quasiparticles can encode quantum information immune from environmental noise with the potential to realize topological quantum computation. Here we propose that phonons, a bosonic excitation of lattice vibrations, can carry non-Abelian charges in their band structures that can be braided using external stimuli. Taking some earthly abundant materials such as silicates...
The stability of a material is an important consideration, particularly in systems with multiple competing phases, and is an area where modelling can provide valuable input to experiments.
However, a typical athermal DFT calculation on an equilibrium structure only yields the lattice energy, which provides limited scope for investigating stability. The theory of lattice dynamics, which...
Properties of materials usually requires to be tuned not only for industrial purpose but also to access to a clear understanding of their origin. Here we will discuss the benefit of using the VASP code in estimating the impact of high-pressure on the magnetic and multiferroic properties of cuprates.
The Joint Automated Repository for Various Integrated Simulations (JARVIS) hosted by the National Institute of Standards and Technology (NIST) is an integrated infrastructure to accelerate materials discovery and design, motivated by the Materials Genome Initiative (MGI). JARVIS uses density functional theory (DFT), beyond DFT methods (GW, DMFT, Quantum Monte Carlo), classical force-fields...
In order to meet society's needs for drastically enhanced procedures for clean renewable energy, there is an urgent need for reliable and efficient sources. One of the most potent sources of energy for the future is electrocatalytic water splitting, which produces H2 and O2 for use in fuel cells containing hydrogen to create electricity. As a result, a lot of studies are being done on...
Recent experiments have demonstrated the potential for ultrafast changes in the functional properties of materials upon selective optical excitation of particular phonon modes. The chemical diversity of complex oxides, and their strong lattice-properties coupling, have made them ideal test systems for new experimental approaches that exploit anharmonic phonon couplings to induce and modify...
