Programming :: Calling Multiple Files In FORTRAN90

I have written FORTRAN code to calculate density profile. This code will open two files ( topology and x,y,z trajectory). The trajectory file contains XYZ data coordinates for multiple frames (about 20 or 100 frames for instance). One frame contains 20736 data.

Previously this code was written to open ONLY one input XYZ data file and do the calculation and would dump the results in separate file and it was running without problem. Recently my data file get bigger in size, so I decided to break the single XYZ data file into few small parts.

Now I have modified the code so that it calls the parts of the XYZ data files ( eg: maltoTHERMO_10Frames.traj, maltoTHERMO_20Frames.traj,... and so on) and do the calculation and dump the results in the same result output file. I have tested this code just with openning the XYZ coordinates and printing into another file to see wheather it collecting the data sequently and it was working fine.

This code supposedly read the x coordinate data and calculate distance and put a count accoding the criteria in the approperiate bins. But when I let the code to do the calculation it stop and shows error. (I have indicated as !** in the code). If I enable this line, it shows error but if I disable this line, than the code do collect only the XYZ coordinates.

The code is as below:

Code:

module all_parameter
integer,parameter :: MAXATOM=20736!CHANGE
integer,parameter :: midwater=1500
integer,parameter :: TOTALFRAMES=20

[Code]....