Kanchan Sarkar

• MSc
• Indian Association for the Cultivation of Science

The magnesium chalcogenide spinel MgSc2Se4 with high Mg‐ion room‐temperature conductivity has recently attracted interest as solid electrolyte for magnesium ion batteries. Its ionic/electronic mixed‐conducting nature and the influence of the spinel composition on the conductivity and Mg²⁺ migration barrier are yet not well understood. Here, results...

The magnesium chalcogenide spinel MgSc2Se4 with high Mg-ion room-temperature conductivity has recently attracted interest as solid electrolyte for magnesium ion batteries. Its ionic/electronic mixed-conducting nature and the influence of the spinel composition on the conductivity and Mg2+ migration barrier are yet not well understood. Here, results...

We present a density functional theory study of the initial steps of chlorine deposition on the Mg(0001) surface. Such processes occur in chloride-ion batteries in which lithium and magnesium are used as anode materials. In addition, it is also of fundamental interest, as halide adsorption on metal electrodes is an important process in interfacial...

We present a density functional theory study of the initial steps of chlorine deposition on the Mg(0001) surface. Such processes occur in chloride-ion batteries in which lithium and magnesium are used as anode materials. In addition, it is also of fundamental interest, as halide adsorption on metal electrodes is an important process in interfacial...

The primary phase of the Earth’s lower mantle, (Al, Fe)‐bearing bridgmanite, transitions to the post‐perovskite (PPv) phase at Earth’s deep mantle conditions. Despite extensive experimental and ab initio investigations, there are still important aspects of this transformation that need clarification. Here, we address this transition in (Al³⁺, Fe³⁺)...

At ambient pressure, bulk SrCoO$_{3}$ is a ferromagnetic (FM) metal in cubic perovskite structure. By contrast, magnetic properties of epitaxial SrCoO$_{3}$ thin films, especially at high tensile strain ($\varepsilon \gtrsim 3$\%), remain unclear: Previous calculations had predicted antiferromagnetic (AFM) states more energetically favorable in thi...

The primary phase of the Earth's lower mantle, (Al, Fe)-bearing bridgmanite, transitions to the postperovskite (PPv) phase at Earth's deep mantle conditions. Despite extensive experimental and ab initio investigations, there are still important aspects of this transformation that need clarification. Here, we address this transition in (Al3+, Fe3+)-...

The presence of nonadiabaticity in the photodetachment bands of the anionic mixed carbon-boron cluster C3B5- has been realized through ab initio electronic structure calculations and detailed analyses of quantum dynamics study on top of those electronic structures. In the course of our study, we traverse extensive first principles electronic struct...

We present ab initio (LDA + Usc) studies of high‐temperature and high‐pressure elastic properties of pure as well as iron‐bearing (ferrous, Fe²⁺, and ferric, Fe³⁺) and aluminum‐bearing MgSiO3 postperovskite, the likely dominant phase in the deep lower mantle of the Earth. Thermal effects are addressed within the quasiharmonic approximation by combi...

We present a bio-inspired stochastic optimization strategy that optimizes projector augmented wave (PAW) datasets, for a user-specified pressure range, to realize the highest possible accuracy in high-throughput density functional theory calculations within the framework of PAW method. We named the optimizer “Evolutionary Generator of projector aug...

This book can be regarded as ‘Soft computing for physicists and chemists self-taught’. It prepares the readers with a solid background of soft computing and how to adapt soft computing techniques to problem solving in physical and chemical research. Soft computing methods have been little explored by researchers in physical and chemical sciences pr...

A novel quantum-classical recipe for locating the global minimum on the potential energy surface of a large molecule and simultaneously predicting the associated electronic charge distribution is developed by interfacing the classical particle swarm optimization with a near optimal unitary evolution scheme for the trial one electron density matrix....

We examine the challenge of performing accurate electronic structure calculations at high pressures by comparing the results of all-electron full potential linearized augmented-plane-wave calculations with those of the projector augmented wave (PAW) method. In particular, we focus on developing an automated and consistent way of generating transfer...

We examine the challenge of performing accurate electronic structure calculations at high pressures by comparing the results of all-electron full potential linearized augmented-plane-wave calculations with those of the projector augmented wave (PAW) method. In particular, we focus on developing an automated and consistent way of generating transfer...

The growth of evolutionary computing (EC) methods in the exploration of complex potential energy landscapes of atomic and molecular clusters, as well as crystals over the last decade or so is reviewed. The trend of growth indicates that pure as well as hybrid evolutionary computing techniques in conjunction of DFT has been emerging as a powerful to...

Computing in theoretical chemistry has been largely and traditionally based on purely numerical 'non- intelligent' computing techniques. The tools of 'Artificial Intelligence' (AI) or ‘Computational Intelligence’ have been little explored and exploited in the context of research in theoretical chemistry. Over the last decade and a half we had been...

A single string based evolutionary algorithm that adaptively learns to control the mutation probability ($p_m$) and mutation intensity ($\Delta_m$), has been developed and used to investigate the ground-state configurations and energetics of 3D clusters of a finite number (N) of `point-like' charged particles. The particles are confined by a harmon...

We propose and implement a simple adaptive heuristic to optimize the geometries of clusters of point charges or ions with the ability to find the global minimum (GM) energy configurations. The approach uses random mutations of a single string encoding the geometry and accepts moves that decrease the energy. Mutation probability and mutation intensi...

A completely adaptive random mutation hill climbing method (CARMHC) developed earlier for unbiased search for the global minimum on the PES of ionic clusters is further strengthened by introducing the idea of fuzzy adaptive control of mutation probability and intensity based on the results of past explorations. The workability of the resulting algo...

A simple adaptive heuristic to optimize the geometries of clusters of charged particles or atoms and find the global minimum energy configurations has been proposed. The approach uses random mutations of one single configuration and accepts moves that decrease the energy. Mutation probability and mutation intensity are allowed to evolve adaptively.

Neutral polythiophene (PT) and polyselenophene (PSe) are semiconductors with band gaps of about 2 eV. We have proposed and implemented a constrained variational method in which total energy of neutral PT or PSe oligomers is minimized under the constraint that the band gap measured by HOMO–LUMO energy difference is also a minimum in each case. The c...

We explore the effect of on and off-center repulsive impurities on regular parabolic dots and their impact on the level structures coupled with a variation in the dot size. Information entropy and probability density are invoked to monitor the pattern of evolution of the electronic states. We have considered Gaussian impurity centers of repulsive t...

We explore the pattern of time evolution of eigenstates of a repulsive impurity doped quantum dot. The quantum dot is two dimensional and contains one electron which is harmonically confined. We have considered Gaussian impurity centers. A static transverse magnetic field is also present. For given strength of confining fields, intensity and oscill...

We explore the pattern of frequency-dependent linear and non-linear optical (NLO) response of electron impurity doped quantum dots harmonically confined in two dimensions. For some fixed values of transverse magnetic field strength (ωc), and harmonic confinement potential (ω0), the influence of impurity location (x0,y0) on the diagonal components o...

A density matrix based soft-computing solution to the quantum mechanical problem of computing the molecular electronic structure of fairly long polythiophene (PT) chains is proposed. The soft-computing solution is based on a “random mutation hill climbing” scheme which is modified by blending it with a deterministic method based on a trial single-pa...