  The spectrum of finite-difference two-magnon operator is investigated for
quantum S=1/2 chain with variable range exchange of the form $h(j-k)\propto
\sinh^{-2}a(j-k)$. It is found that usual bound state appears for some values
of the total pseudomomentum of two magnons as for the Heisenberg chain with
nearest-neighbor spin interaction. Besides this state, a new type of bound
state with oscillating wave function appears at larger values of the total
pseudomomentum.

Exactly Solvable and Integrable Systems;Statistical Mechanics;Exactly Solvable and Integrable Systems