Structure of excited states of 10Be studied with antisymmetrized molecular dynamics

We study the structure of excited states of ¹⁰Be with the method of variation after spin-parity projection in the framework of antisymmetrized molecular dynamics. Present calculations describe many excited states and reproduce the experimental data of E2 and E1 transitions and the new data of the β transition strength successfully. We include systematic discussions on the moleculelike structures of light unstable nuclei and the important role of the valence neutrons based on the results obtained with the framework which is free from such model assumptions as the existence of inert cores and clusters.