Crystalline order and disorder in dusty plasmas investigated by nonequilibrium molecular dynamics simulations*

Abstract

The particle structure of a complex system has been explored through a unique Evans's homogenous nonequilibrium molecular dynamics (HNEMD) simulation technique. The crystalline order–disorder structures (OD-structures) and the corresponding energies of three-dimensional (3D) nonideal complex systems (NICSs) have been measured over a wide range of plasma states (Γ, κ) for a body-centered cubic (BCC) structure. The projected technique provides accurate OD-structures with fast convergence and applicable to very small size effect for different temperatures ( ≡ 1 / Γ ) and constant force field ( F * ) values. The OD-structure obtained through HNEMD approach is found to be reasonable agreement and more reliable than those earlier identified by simulation approaches and experimental data of NICSs. New simulations of OD-structures show that dusty plasma remains in crystalline (strongly coupled) state at lower temperature and constant F * values, for the whole simulation runs. Our investigations show that the crystalline structure is changed and the particle structure switches from intermediate to disorder (nonideal gaseous) state with an increase of the system's temperature. It has been shown that the long range order shifts toward lower temperature with increasing * κ . The presented technique exhibits that the potential energy has a maximum value when the dusty plasma remains in crystalline states (low temperatures), which confirms earlier 3D simulation results.