Structures and properties of the potassium-doped carbon clusters KCn/KCn+/KCn−(n = 1−10) Hui Wang and Guoliang Li Eur. Phys. J. D, 68 7 (2014) 182 Published online: 01 July 2014 DOI: 10.1140/epjd/e2014-50286-0