Problem of locally disordered atomic structure is solved by using a hybrid formulation in which nonlinear elastic finite elements are linked with discrete atomic interaction elements. The continuum approach uses nonlinear hyperelasticity based upon the generalized strain while the atomistic approach employs the Tight-Binding Second-Moment Approximation potential to create new type of elements. The molecular interactions yielding from constitutive models of TB SMA were turned into interactions between nodes to solve a boundary value problem by means of finite element solver. Atomistic psudoelements are noting more than two-node atomic interaction. The application is used to deal with the problem of edge dislocation and its dissociation into two Schockley's dislocation in Cu crystals.

Three examples are shown. In the first, the whole considered crystal region has been discretized and solved by means of the nonlinear elastic FEs. In the second example, the same FE region has been discretized by means of the molecular lattice and solved by molecular dynamics and statics. Finally, in the third example the regions around the dislocations' cores have been replaced by discretized atomic structure and linked on the boundary with corresponding nodes of continuum FEs. In this way, a single boundary value problem with two different types of discretization of the crystal structure has been solved in this example. A transition on the continuum/atomic interface is assured by taking into account a crystallographic data in the finite element mesh preparation. In this example the regions of dislocation cores were modelled using molecular interaction mesh while the ordered lattice was discretized by FEs. The obtained MD-FE model has been applied to simulate the nanoindentation test on nanocrystalline copper in order to conclude on the singularities observed in P-h curves.