Ab Initio Molecular Dynamics of Dimerization and Clustering in Alkali Metal Vapors.
Alkali metals are known to form dimers, trimers, and tetramers in their vapors. The mechanism and regularities of this phenomenon characterize the chemical behavior of the first group elements. We report ab initio molecular dynamics (AIMD) simulations of the alkali metal vapors and characterize their structural properties, including radial distribution functions and atomic cluster size distributions. AIMD confirms formation of Men, where n ranges from 2 to 4. High pressure sharply favors larger structures, whereas high temperature decreases their fraction. Heavier alkali metals maintain somewhat larger fractions of Me2, Me3, and Me4, relative to isolated atoms. A single atom is the most frequently observed structure in vapors, irrespective of the element and temperature. Due to technical difficulties of working with high temperatures and pressures in experiments, AIMD is the most affordable method of research. It provides valuable understanding of the chemical behavior of Li, Na, K, Rb, and Cs, which can lead to development of new chemical reactions involving these metals.
Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo , 12231-280 São José dos Campos, SP Brazil.
Vitaly V
VV
Chaban
Departments of Chemistry, Physics and Astronomy, University of Southern California , Los Angeles, California 90089, United States.
Oleg V
OV
Prezhdo