Spin-vibrational resonances and coupling in Ln-based single-molecule magnets in different environmentsDaria D. Nakritskaia, Sergey A. Varganov*Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia Street, Reno, NV 89557-0216, United States.svarganov@unr.edu

Lanthanide-based single-molecule magnets (Ln-based SMMs) are of high interest because of their potential applications as qubits and building blocks for high-density memory materials. One of the main challenges is increasing the spin relaxation and decoherence times, which requires detailed understanding of the electronic structure and spin dynamics in Ln-based SMMs. Most electronic structure calculations are done on isolated SMMs assuming ideal gas conditions whereas the experiments are performed in the condensed phase environments. Interaction between electron spin and molecular vibrations is one of the important mechanisms responsible for spin relaxation and decoherence. The rate of spin relaxation depends on the presence of spin-vibrational resonances and on the magnitude of spin-vibrational couplings which are affected by their environments. We investigate these effects in Ln-terpyridine complexes using ab initio multireference electronic structure methods. The calculations are performed on the molecular structures sampled from the molecular dynamics simulations in the gas, solution, and crystal phases. While in many cases energies of the spin and vibrational transitions are not significantly affected by the SMMs environment, coordination of the solvent molecules to Ln can lead to a large increase of magnetic anisotropy barrier. This effect can improve the magnetic properties of Ln-based SMMs in solutions and open new direction in designing high-temperature SMMs.