Electronic and optical properties of CuGaS2 nanowires: a study of first principle calculations Payman Nayebi, Mohsen Emami-Razavi and Esmaeil Zaminpayma Eur. Phys. J. B, 90 1 (2017) 11 Published online: 18 January 2017 DOI: 10.1140/epjb/e2016-70061-3