  The inherent nodal structures of the wavefunctions of 4-nucleon systems have
been investigated. The quantum numbers of the excited states (resonances) have
been deduced. It was found that all the T=0 even-parity resonances are
dominated by {2,1,1} component with L=1, all the T=0 odd-parity resonances are
dominated by {3,1} component with L=1, and all the T=1 odd-parity resonances
are also dominated by {3,1} component with L=1. The understanding of the
inherent nodal structure is found to be crucial to a systematic understanding
of the spectrum.
