This paper proves existence and stability results of solitary-wave solutions
to coupled nonlinear Schr\"{o}dinger equations with power-type nonlinearities
arising in several models of modern physics. The existence of solitary waves is
obtained by solving a variational problem subject to two independent
constraints and using the concentration-compactness method. The set of
minimizers is shown to be stable and further information about the structures
of this set are given. The paper extends the results previously obtained by
Cipolatti and Zumpichiatti, Nguyen and Wang, and Ohta