title: Exploring N-Rich Phases in Li(x)N(y) Clusters for Hydrogen Storage at Nanoscale.
abstract: We have performed cascade genetic algorithm and ab initio atomistic thermodynamics under the framework of first-principles-based hybrid density functional theory to study the (meta-)stability of a wide range of Li(x)N(y) clusters. We found that hybrid xc-functional is essential to address this problem as a local/semilocal functional simply fails even to predict a qualitative prediction. Most importantly, we find that though in bulk lithium nitride, the Li-rich phase, that is, Li3N, is the stable stoichiometry; in small Li(x)N(y) clusters, N-rich phases are more stable at thermodynamic equilibrium. We further show that these N-rich clusters are promising hydrogen storage material because of their easy adsorption and desorption ability at respectively low (≤300 K) and moderately high temperature (≥600 K).
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Amrita
authors.initials: A
authors.lastname: Bhattacharya
authors.affiliation: Department of Physics, Indian Institute of Technology Delhi, Hauz Khas , 110016 New Delhi, India.
authors.forename: Saswata
authors.initials: S
authors.lastname: Bhattacharya
keywords: Li−N−H clusters; atomistic thermodynamics; cascade genetic algorithm; density functional theory; hybrid functional; hydrogen storage; meta stability; thermodynamic phase diagram