2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008

Self-compression of metallic clusters under surface tension

Authors: J.P. Perdew, M. Brajczewska and C. Fiolhais

Ref.: Solid State Communications 88, 795-801 (1993)

Abstract: The stabilized jellium model is used to explore the physics of self-compression for spherical clusters of simple-metal atoms. Within the continuum or liquid drop model, strong compression of the interior ionic density of a small cluster (with respect to the bulk density) results from cooperation between surface tension and surface suppression of the elastic stiffness. The latter effect is due to the large negative value of sigma'', the second derivative of surface tension with respect to uniform strain. Self-compression also renormalizes the effective curvature-energy coefficient, and contributes to the asymptotic (large-radius) size effect on the ionization energy. A quantum-mechanical calculation of interior density as a function of electron number displays small shell-structure oscillations around the average behavior predicted by the liquid drop model. Numerical results are presented for clusters of Al, Na, and Cs. For compact 6-atom clusters of these metals, predicted bond lengths are smaller than their bulk values by 10%, 6%, and 4%, respectively.