  We study electrostatic and phonon properties of Yukawa crystals. It is shown
that in the harmonic approximation these systems which is in use in the theory
dusty plasma can be described analytically by the model from the theory of
neutron stars and white dwarfs. Using this approximation we consider properties
of body-centred cubic (bcc), face-centred cubic (fcc), hexagonal close-packed
(hcp), and MgB$_2$ lattices. MgB$_2$ and hcp lattices have never been studied
earlier in the context of Yukawa systems. It is shown that they never possess
the smallest potential energy and the phase diagram of stable Yukawa crystals
contains bcc and fcc lattices only. However, corrections to the charge density
$\propto (\kappa a)^4$ can noticeably change the structural diagram of Yukawa
systems. The developed analytical model also allows to describe low-temperature
effects where numerical simulations are difficult.
