Pyrrhotite superstructures. Part I: Fundamental structures of the NC (N = 2, 3, 4 and 5) type Pósfai, Mihály; Dódony, István European Journal of Mineralogy Volume 2 Number 4 (1990), p. 525 - 528 10.1127/ejm/2/4/0525 https://www.schweizerbart.de/papers/ejm/detail/2/82593/Pyrrhotite_superstructures_Part_I_Fundamental_stru?af=crossref 谢谢!