Modelling longrange interactions in multiscale simulations of ferromagnetic materials Atomisticcontinuum multiscale modelling is becoming an increasingly popular tool for simulating the behaviour of materials due to its computational efficiency and reliable accuracy. In the case of ferromagnetic materials, the atomistic approach handles the dynamics of spin magnetic moments of individual atoms, while the continuum approximations operate with volumeaveraged quantities, such as magnetisation. One of the challenges for multiscale models in relation to physics of ferromagnets is the existence of the longrange dipoledipole interactions between spins. The aim of the present paper is to demonstrate a way of including these interactions into existing atomisticcontinuum coupling methods based on the partitioneddomain and the upscaling strategies. This is achieved by modelling the demagnetising field exclusively at the continuum level and coupling it to both scales. Such an approach relies on the atomistic expression for the magnetisation field converging to the continuum expression when the interatomic spacing approaches zero, which is demonstrated in this paper.

Computational Generation of Polymer Chains For the development of polymeric amorphous materials with desired properties new algorithms are needed to help in the process of rationalizing the relationship between the atomic structure and the macroscopic observables. Even though numerical simulations, such as Molecular Dynamics, have become an efficient tool for giving a detailed description of the structural changes in atomic arrangements under different temperature and pressure, the computation time that can be simulated are below the time span of relevant physical and chemical phenomena. In this work an algorithm to replicate the equilibrium structure in linear homopolymers is developed. The algorithm focuses on performing local movements of dihedral angles to minimize the total potential energy. The procedure generates chains of arbitrary length in a simulation volume with the constrain of a fixed endtoend radius. Preliminary results show that the algorithm succeed in decreasing the potential energy substantially while approximating the target averaged endtoend radius asymptotically.