Result before commenting out Line 5-55, Line 63-68

before commenting

❯ ./md                                                                                                demo 8
 Molecular Dynamics Simulation example program
 ---------------------------------------------
 number of particles is ............  13500
 side length of the box is .........     25.323179
 cut off is ........................      3.750000
 reduced temperature is ............      0.722000
 basic timestep is .................      0.064000
 temperature scale interval ........     10
 stop scaling at move ..............     20
 print interval ....................      5
 total no. of steps ................     20

    i       ke         pe            e         temp      pres      vel      rp
  -----  ----------  ----------  ----------  --------  --------  --------  ----
before forces in main: f[1394] = 0.00000000000000000000, f_accumulation[0][1394] = 0.00000000000000000000
right after loop     : f[1394] = -0.00784321825777483522, f_accumulation[0][1394] = -0.00784321825777483522
in forces            : f[1394] = -0.00784321825777483522, f_accumulation[0][1394] = -0.00784321825777483522
after forces in main : f[1394] = -0.00784321825777483522, f_accumulation[0][1394] = -0.00784321825777483522
--------------------------------------------------
before forces in main: f[1394] = 0.00000000000000000000, f_accumulation[0][1394] = 0.00000000000000000000
right after loop     : f[1394] = -0.01673827827831624732, f_accumulation[0][1394] = -0.01673827827831624732
in forces            : f[1394] = -0.01673827827831624732, f_accumulation[0][1394] = -0.01673827827831624732
after forces in main : f[1394] = -0.01673827827831624732, f_accumulation[0][1394] = -0.01673827827831624732
--------------------------------------------------
before forces in main: f[1394] = 0.00000000000000000000, f_accumulation[0][1394] = 0.00000000000000000000
right after loop     : f[1394] = -0.02747964736370374014, f_accumulation[0][1394] = -0.02747964736370374014
in forces            : f[1394] = -0.02747964736370374014, f_accumulation[0][1394] = -0.02747964736370374014
after forces in main : f[1394] = -0.02747964736370374014, f_accumulation[0][1394] = -0.02747964736370374014
--------------------------------------------------
before forces in main: f[1394] = 0.00000000000000000000, f_accumulation[0][1394] = 0.00000000000000000000
right after loop     : f[1394] = -0.04075080159338838326, f_accumulation[0][1394] = -0.04075080159338838326
in forces            : f[1394] = -0.04075080159338838326, f_accumulation[0][1394] = -0.04075080159338838326
after forces in main : f[1394] = -0.04075080159338838326, f_accumulation[0][1394] = -0.04075080159338838326
--------------------------------------------------
before forces in main: f[1394] = 0.00000000000000000000, f_accumulation[0][1394] = 0.00000000000000000000