  Heavy-ion collisions at the Relativistic Heavy Ion Collider at Brookhaven
National Laboratory and the Large Hadron Collider at CERN probe matter at
extreme conditions of temperature and energy density. Most of the global
properties of the collisions can be extracted from the measurements of charged
particle multiplicity and pseudorapidity ($\eta$) distributions. We have shown
that the available experimental data on beam energy and centrality dependence
of \Eta-distributions in heavy-ion (Au+Au or Pb+Pb) collisions from \sNN=7.7
GeV to 2.76 TeV are reasonably well described by the AMPT model, which is used
for further exploration. The nature of the \Eta-distributions has been
described by a double Gaussian function using a set of fit parameters, which
exhibit a regular pattern as a function of beam energy. By extrapolating the
parameters to a higher energy of \sNN~=~5.02 TeV, we have obtained the charged
particle multiplicity densities, \Eta-distributions and energy densities for
various centralities. Incidentally, these results match well with some of the
recently published data by the ALICE collaboration.
