Computer simulations of metal-liquid ammonia solutions

In this report three kinds of simulations of metal-ammonia solutions are discussed. the single ion approach the electron is neglected. The interest is concentrated on the solvation shell of the ions. Its dependence on ionic size and charge and the importance of many-body contributions to the ion-ammonia potential are investigated. In a quantum simulation of a 9 MPM (mole percent metal) lithium-ammonia solution the electrons as well as the ions are treated explicitly. Good agreement is found for some dynamical properties of the solution. In the third approach the pseudopotential theory is employed in a Monte Carlo calculation of a 11.64 MPM lithium-ammonia solution. In this way the electrons can be excluded from explicit consideration and classical simulations can be performed. From these calculations cluster formation between solvated lithium ions are deduced. The two latter simulations do not yet lead to a comprehensive description of concentrated metal-ammonia solutions. Further improvements are necessary. the single ion approach the electron is neglected. (C) 2000 Elsevier Science B.V. All rights reserved.