Actinides computer simulation

It is possible that soluble actinides may occur as a result of complexation of the actinides with iron chelators such as ferrioxamine. Stumm and Morgan (46) believe, on the basis of computer simulation studies, that soluble Fe(III) in seawater exists almost exclusively as a ferrioxamine chelate. A similar study with the actinides would be of considerable interest. 

The difficulties of experimentally determining the speciation of actinides present at very low concentrations in natural waters have encouraged the use of computer simulations, based on thermodynamic data, as a means of predicting their speciation and hence their environmental behaviour. The use of modelling techniques to describe the speciation, sorption, solubility and kinetics of inorganic systems in aqueous media has been reviewed in the papers given at an international conference in 1978. Both chemical equilibrium models, exemplified by computer programs such as MINEQL and SOLMNQ, and dynamic reaction path models, exemplified by EQ6, have been developed. Application of the equilibrium models to radioactive waste disposal... 

The papers presented in the conference span the spectrum of activity in the science of alloys. The theoretical presentations ranged in content from fundamental studies of electronic structure, to first-principles calculations of phase diagrams, to the effects of charge transfer, to the temperature dependence of short-range order parameters. They encompassed the study of mechanical properties, the properties of dislocations, of phase evolution, and computer simulations. Experimental studies were presented based on a variety of state of the art experimental techniques, from TEM to synchrotron diffraction. The phenomena studied varied from the precipitation of nitrides in steel, to the wetting of interfaces between two different crystal structures, to the ordering of vacancies in carbides. And the materials whose properties were measured ranged from Transition metals, to the Lanthanides, to the Actinide series of compounds and alloys. 

Chaumont and Wipff have over several years examined the solvation of a number of lanthanide and actinide species in a basic [EMIMjCl-AlCls melt (excess anions present), and in [BMIMjlPFe] [42-45]. The ab initio computations were primarily used to assess the accuracy of more detailed classical simulations. 

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