Electronic and optical properties of pristine and alkali metal atom-adsorbed QPHT-graphene: first-principles calculationsTian-Chong Qiu, Zhi-Gang Shao, Cang-Long Wang and Lei YangEur. Phys. J. B, 96 7 (2023) 103DOI: https://doi.org/10.1140/epjb/s10051-023-00572-5