We use the novel constitutive model in Nika and Vernescu (Z Angew Math Phys 71:1–19, 2020), derived using the homogenization method, to investigate the effect particle chain microstructures have on the properties of the magnetorheological fluid. The model allows to compute the constitutive coefficients for different geometries. Different geometrical realizations of chains can significantly alter the magnetorheological effect of the suspension. Numerical simulations suggest that particle size is also important as the increase in the overall particle surface area can lead to a decrease in the overall magnetorheological effect while keeping the volume fraction constant.