  We propose a new quantum computational way of obtaining a ground-state energy
and expectation values of observables of interacting Hamiltonians. It is based
on the combination of the adiabatic quantum evolution to project a ground state
of a non-interacting Hamiltonian onto a ground state of an interacting
Hamiltonian and the phase estimation algorithm to retrieve the ground-state
energy. The expectation value of an observable for the ground state is obtained
with the help of Hellmann-Feynman theorem. As an illustration of our method, we
consider a displaced harmonic oscillator, a quartic anharmonic oscillator,and a
potential scattering model. The results obtained by this method are in good
agreement with the known results.
