  We apply tensor version of antisymmetrized quasi cluster model (AQCM-T) to
4He and 8Be while focusing on the NN correlations in alpha clusters. We adopt
the NN interactions including realistic ones containing a repulsive core for
the central part in addition to the tensor part. In 4He, the pn pair in the 3D
channel has been known to play a decisive role in the tensor correlation and
the framework is capable of treating not only this channel but also the NN
correlations in the 1S and 3S channels. In 8Be, when two alpha clusters
approach, the 3D pair is suppressed because of the Pauli blocking effect, which
induces the decrease of the 3S component through the 3S-3D coupling. This
effect results in the reduction of the attractive effect of the central-even
interaction in the middle-range region.
