  Heavy elements (beyond iron) are formed in neutron capture nucleosynthesis
processes. We have proposed a simple unified model to investigate the neutron
capture nucleosynthesis in arbitrary neutron density environment. We have also
investigated what neutron density is required to reproduce the measured
abundance of nuclei assuming equilibrium processes. We found both of these that
the medium neutron density has a particularly important role at neutron capture
nucleosynthesis. About these results most of the nuclei can formed at medium
neutron capture density environment e.g. in some kind of AGB stars. Besides
these observations our model is capable to use educational purpose.
