Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
J. Phys.: Condens. Matter 12 (2000) 51095119. Printed in the UK PII: S0953-8984(00)13414-9 Tight binding molecular dynamics studies of the viscosity of
 

Summary: J. Phys.: Condens. Matter 12 (2000) 5109­5119. Printed in the UK PII: S0953-8984(00)13414-9
Tight binding molecular dynamics studies of the viscosity of
liquid selenium
R Stadler, D R Bowler, D Alf`e and M J Gillan
Physics and Astronomy Department, University College London, Gower Street, London
WC1E 6BT, UK
Geology Department, University College London, Gower Street, London WC1E 6BT, UK
Received 20 April 2000
Abstract. A tight binding technique is employed to study the influence of the size of the unit
cell on molecular dynamics simulations of liquid selenium at 870 K. Systems with 69, 138, 276
and 552 atoms have been studied within the Fermi operator expansion method. The Green­
Kubo formula has been used to calculate the shear viscosity for all systems from the off-diagonal
component of the stress tensor. No dependence on the cell size could be found within the error
bars defined by statistical accuracy. For the two smallest systems calculations up to 60 ps have
been performed where the viscosities become identical. These findings indicate that the recently
reported disagreement of DFT calculations and experiments on the viscosity of liquid selenium at
870 K must be attributed to a deficiency in the chosen exchange correlation functional rather than
size effects.
1. Introduction
Liquid selenium (l-Se) is a much studied system exhibiting very unusual properties. The

  

Source: Alfè, Dario - Departments of Earth Sciences & Physics and Astronomy, University College London

 

Collections: Physics; Geosciences