Spin-polarized DFT investigation of electronic and magnetic properties of bare and hydrogenated α-graphyne nanoribbons

In this work, a first-principles study is presented on zigzag- and armchair-edged [Formula: see text]-graphyne nanoribbons ([Formula: see text] GNRs) with varying widths in both hydrogen-passivated and unpassivated forms. Spin-polarized density functional theory (DFT) calculations are employed to investigate their stability, structural and electronic properties. Formation energy and edge formation energy analyses confirm that all passivated [Formula: see text] GNRs are energetically stable. Armchair nanoribbons are identified as nonmagnetic direct-gap semiconductors, with a width-dependent band gap showing periodic oscillations due to quantum confinement and lattice symmetry. In contrast, zigzag nanoribbons exhibit magnetic metallic behavior, except at the narrowest widths. Partial density of states analysis reveals that carbon p-orbitals dominate the electronic contributions. These findings suggest that [Formula: see text] GNRs, with tunable band gaps governed by edge geometry and ribbon width, are promising candidates for future optoelectronic and spintronic applications.