▎ 摘　　要

Patterned vacancy clusters (or nanoholes) can modify the electronic structure of graphene, and thereby generate entirely new functionalities. Knowledge of the relative stability of various nanoholes and associated properties is essential for the rational design and fabrication of practical devices. Extensive first-principles results reveal remarkable stability in certain ring configurations, as well as modified triangular and hexagonal vacancy configurations. The identified magic numbers of vacancies are 2, 4, 6, 28, 39, 42, 52, and 60. A large number of the nanoholes exhibit magnetic states with diverse energy band-gap values. Some large nanoholes possess nonzero net moments in all possible magnetic solutions, showing that the corresponding magnetization is robust against thermal fluctuation. Room-temperature ferromagnetism in graphene (and graphite) can be attributed to the local ferri-or ferromagnetism in large nanoholes, which can be created under irradiation and chemical treatment. Nanohole-induced, stable magnetic-semiconducting graphene is expected to be useful in graphene-based spintronics.