October  6 2025   6:29:55.240 PM
 
md():
  Fortran90 version
  A molecular dynamics program.
 
  Enter ND, the spatial dimension (2 or 3 ):
 
  Enter NP, the number of particles (500, for instance):
 
  Enter STEP_NUM, the number of time steps (500, for instance):
 
  ND, the spatial dimension, is        3
  NP, the number of particles in the simulation is     1000
  STEP_NUM, the number of time steps, is      400
  DT, the size of each time step, is   0.100000E-03
 
  Initializing positions, velocities, and accelerations.
 
  Computing initial forces and energies.
 
  At each step, we report the potential and kinetic energies.
  The sum of these energies should be a constant.
  As an accuracy check, we also print the relative error
  in the total energy.
 
      Step      Potential       Kinetic        (P+K-E0)/E0
                Energy P        Energy K       Relative Energy Error
 
         0     498036.         0.00000         0.00000    
        40     498036.        0.598500E-01    0.200455E-10
        80     498035.        0.248846        0.183807E-10
       120     498035.        0.567165        0.137688E-10
       160     498035.         1.01496        0.468141E-11
       200     498034.         1.59242       -0.103954E-10
       240     498033.         2.29984       -0.329563E-10
       280     498032.         3.13753       -0.645602E-10
       320     498031.         4.10589       -0.106674E-09
       360     498030.         5.20536       -0.160752E-09
       400     498029.         6.43646       -0.228479E-09
 
  Elapsed cpu time for main computation:
     11.0829     seconds
 
md():
  Normal end of execution.
 
October  6 2025   6:30:06.356 PM