  The preparation of entangled quantum states is an inherent and indispensable
step for the implementation of many quantum information algorithms. Depending
on the physical system, there are different ways to control and measure them,
which allow one to achieve the predefined quantum states. The diamond spin
cluster is the system that can be applied for this purpose. Moreover, such a
system appears in chemical compounds such as the natural mineral azurite, where
the $Cu^{2+}$ are arranged in a spin-1/2 diamond chain. Herein, we propose the
method of preparation of pure entangled states on the Ising-Heisenberg spin-1/2
diamond cluster. We suppose that the cluster consists of two central spins
which are described by an anisotropic Heisenberg model and interact with the
side spins via Ising interaction. Controlling the measurement direction of the
side (central) spins allows us to achieve predefined pure quantum states of the
central (side) spins. We show that this directly affects the entanglement and
fidelity of the prepared states. For example, we obtain conditions and
fidelities for preparations of the Bell states.
