  Multi-particle collision dynamics (MPCD) is a mesoscopic simulation method to
simulate fluid particle-like flows. MPCD has been widely used to simulate
various problems in condensed matter. In this study, hydrostatic behavior of
gas in the Earth's atmospheric layer is simulated by using MPCD method. The
simulation is carried out by assuming the system under ideal state and is
affected only by gravitational force. Gas particles are homogeneous and placed
in 2D box. Interaction of the particles with the box is applied through
implementation of boundary conditions (BC). Periodic BC is applied on the left
and the right side, specular reflection on the top side, while bounce-back on
the bottom side. Simulation program is executed in Arch Linux and running in
notebook with processor Intel i5 @2700 MHz with 10 GB DDR3 RAM. The results
show behaviors of the particles obey kinetic theory for ideal gas when
gravitational acceleration value is proportional to the particle mass. Density
distribution as a function of altitude also meets atmosphere's hydrostatic
theory.
