October  6 2025   6:30:17.798 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     498090.         0.00000         0.00000    
        40     498090.        0.555222E-01    0.186113E-10
        80     498090.        0.230850        0.171226E-10
       120     498090.        0.526147        0.130055E-10
       160     498089.        0.941543        0.489370E-11
       200     498089.         1.47722       -0.854329E-11
       240     498088.         2.13343       -0.286666E-10
       280     498087.         2.91045       -0.568253E-10
       320     498086.         3.80864       -0.943703E-10
       360     498085.         4.82839       -0.142676E-09
       400     498084.         5.97017       -0.203214E-09
 
  Elapsed cpu time for main computation:
     11.4556     seconds
 
md():
  Normal end of execution.
 
October  6 2025   6:30:29.285 PM