Abstract

Classical molecular dynamics simulations of ionic charge transport in condensed phase systems subject to an external magnetic field are surprisingly uncommon. This is due to two main difficulties. First, the non-canonical form of the Hamiltonian breaks standard time reversal invariance and key statistical relations do not hold in standard form. Second, the coupling between coordinates and momenta induced by the Lorentz force hinders straightforward application of common algorithms (e.g. velocity Verlet, Nose-Hoover thermostat) and of the periodic boundary conditions usually applied for bulk simulations. Recent work showing how these conceptual and practical difficulties can be circumvented will be presented in this talk. A set of generalized time reversal operations [1,2] enabling to reinstate standard properties of time-correlation functions under the symmetry and predict null transport coefficients will be illustrated. A new, Liovillian-based, integration algorithm for these systems will then be presented [3]. Finally, the application of these develpoments to charge transport in molten NaCl and in the superionic phase of AgI, with specific focus on detecting the possible on-set of the ionic Hall effect in these systems, will be discussed [4].

[1] S. Bonella, G. Ciccotti and L. Rondoni EPL 108 60004 (2014) [2] S. Bonella, A. Coretti, L. Rondoni and G. Ciccotti, Phys. Rev. E 96 012160 (2017) [3] F. Mouhat, S. Bonella and C. Pierleoni Mol. Phys. 111 3651 (2013) [4] L. Gagliardi, S. Bonella. Phys. Rev. B 94 134426 (2016)