Input file for a large 3D cartesian grid       ! Title     
3500 100 5  'Old' 'm' .F.                      ! MaxNum_Elem, Longest, ElemNameLength, FormatType, LengthUnits, media_by_number  
Regions
 3                                             ! ==> # of heterogeneous media regions
'METEC'                                        ! Region #1: Name of dominant medium  
'Atmos'                                        ! Region #3: medium name 
'cartesian'   'm'                              !    coordinates, units
0.0e0 0.5e1 0.0e0 0.5e1 0.0e0  0.2e1           !    Rmin, Rmax, Zmin, Zmax
'MSand'                                        ! Region #2: medium name 
'cartesian'   'm'                              !    coordinates, units
0.0e0 0.5e1 0.0e0 0.5e1 -0.2e1 0.0e0           !    Xmin, Xmax, Ymin, Ymax, Zmin, Zmax
Boundaries
1                                              ! ==> # of boundaries
'I' 'TopBB'                                    ! Boundary #1: type and medium name 
'cartesian'   'm'                              !    coordinates, units
0.0e0 0.5e1 0.0e0 0.5e1 0.1e1  0.2e1         !    Rmin, Rmax, Zmin, Zmax
XYZ------1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
       00.  0.0e00    0.0e00    0.2e1   
NX       3        
    0.22e1  0.1000e0  0.2700e1  
NY      50  0.1000e0      
NZ      22        
     0.1e1     0.1e1    0.10e0    0.10e0    0.10e0    0.10e0    0.10e0    0.10e0
     0.1e0    0.10e0    0.10e0    0.10e0    0.10e0    0.10e0    0.10e0    0.10e0
     0.1e0    0.10e0    0.10e0    0.10e0    0.10e0    0.10e0 


    
ENDFI----1----*----2----*----3----*----4----*----5----*----6----*----7----*----8