Early metallization in molecular fluids: the case of iodine

We report a study of structural and electronic properties of I-2 as it appr oaches the metallization in the fluid phase. Electronic properties have bee n investigated by measuring the absorption spectra of the fluid I-2 along t he melting line up to 700 K, while molecular structural properties, namely molecular bond length and bond length distributions, have been determined b y means of EXAFS measurements carried out across the metallization transiti on. The results, supported also by molecular dynamic simulations on fluid I -2 and by comparison with theoretical calculations performed on the hydroge n plasma, suggest a possible microscopic description of the metallization t ransition. (C) 1999 Published by Elsevier Science B.V. All rights reserved.