PUB - Publikationen an der Universität Bielefeld

Thirty-five years after its synthesis, magnetic observables are calculated for the molecular nanomagnet Mn-12-acetate using a spin Hamiltonian that contains all spins. Starting from a very advanced density functional theory parametrization [V. V. Mazurenko et al., Phys. Rev. B 89, 214422 (2014)], we evaluate magnetization and specific heat for this anisotropic system of 12 manganese ions with a staggering Hilbert space dimension of 100 000 000 using the finite-temperature Lanczos method. We compare the results with those obtained from other parametrizations. Our investigations demonstrate that it is now possible to assess the quality of parametrizations of effective spin Hamiltonians for rather large magnetic molecules.