The triaxial deformation in 10 Be is investigated using a microscopic α+α+n+n model. The states of two valence neutrons are classified based on the molecular-orbit (MO) model, and the π-orbit is introduced about the axis connecting the two α-clusters for the description of the rotational bands. There appear two rotational bands comprised mainly of K π = 0 + and K π = 2 + , respectively, at low ...
