Quantum ground-state entanglement for spin-1/2 alternating Heisenberg model in one spatial dimension Chunhuan Xiang, Yao Heng Su and Honglei Wang Eur. Phys. J. Plus, 130 5 (2015) 95 Published online: 21 May 2015 DOI: 10.1140/epjp/i2015-15095-3