diff --git a/Source_files/Little_subroutines.f90 b/Source_files/Little_subroutines.f90
index 37e57793..e96fcf8f 100644
--- a/Source_files/Little_subroutines.f90
+++ b/Source_files/Little_subroutines.f90
@@ -858,7 +858,7 @@ end subroutine interpolate_data_on_grid
 
 
 
-pure subroutine linear_interpolation(xarray, yarray, x, y, i, x0, y0, replac)
+ subroutine linear_interpolation(xarray, yarray, x, y, i, x0, y0, replac)
    real(8), dimension(:), intent(in) :: xarray, yarray	! x-array, y-array
    real(8), intent(in) :: x   ! input
    real(8), intent(out) :: y  ! output
@@ -868,29 +868,35 @@ pure subroutine linear_interpolation(xarray, yarray, x, y, i, x0, y0, replac)
 
    !Check if there is even a need to interpolate:
    if (i > 1) then
-      if ( abs(yarray(i) - yarray(i-1) < 1.0d-6*yarray(i) ) ) then
+      if ( abs(yarray(i) - yarray(i-1)) < 1.0d-6*abs(yarray(i)) ) then
+         !print*, 'L-1:', x, xarray(i-1), xarray(i), abs(x - xarray(i-1)), 1.0d-6*xarray(i-1)
          y = yarray(i)  ! if the values are the same, no need to interpolate
          return
       endif
    endif
 
 
-   REDO: if (.not.present(replac)) then
+   REDO: if (.not.present(replac)) then   ! default
     if (i .GT. 1) then
       if ( abs(x - xarray(i-1)) .GE. 1.0d-6*xarray(i-1)) then
          y = yarray(i-1) + (yarray(i) - yarray(i-1))/(xarray(i) - xarray(i-1))*(x - xarray(i-1))
+         !print*, 'L0:', x, xarray(i-1), xarray(i), abs(x - xarray(i-1)), 1.0d-6*xarray(i-1)
       else
          if (present(y0) .and. present(x0)) then
             y = y0 + (yarray(i) - y0)/(xarray(i) - x0)*(x - x0)
+            !print*, 'L1:', x, xarray(i-1), xarray(i), abs(x - xarray(i-1)), 1.0d-6*xarray(i-1)
          else
             if (present(x0)) then
                y = (yarray(i) - 0.0d0)/(xarray(i) - x0)*(x - x0)
+               !print*, 'L2:', x, xarray(i-1), xarray(i), abs(x - xarray(i-1)), 1.0d-6*xarray(i-1)
             else
                y = (yarray(i) - 0.0d0)/(xarray(i) - 0.0d0)*(x - 0.0d0)
+!                print*, 'y0:', x0, xarray(i-1), xarray(i), abs(x - xarray(i-1)), 1.0d-6*xarray(i-1)
+!                pause 'linear_interpolation'
             endif
          endif
       endif
-    else
+    else ! (i=1)
       if (present(y0) .and. present(x0)) then
          y = y0 + (yarray(i) - y0)/(xarray(i) - x0)*(x - x0)
       else
@@ -990,7 +996,7 @@ subroutine Find_monotonous_LE(Array, Value0, Number)    ! monotoneausly increasi
    real(8) temp_val, val_1, val_2
 
    if (isnan(Value0)) then
-        print*, 'The subroutine Find_in_monotonous_1D_array'
+        print*, 'The subroutine Find_monotonous_LE'
         print*, 'cannot proceed, the value of Value0 is', Value0
         write(*, '(f25.16,f25.16,f25.16,f25.16)') Value0, Array(i_cur), Array(i_1), Array(i_2)
         pause 'STOPPED WORKING...'
@@ -1018,7 +1024,7 @@ subroutine Find_monotonous_LE(Array, Value0, Number)    ! monotoneausly increasi
                 coun = coun + 1
                 if (coun .GT. 1e3) then
                     print*, 'PROBLEM WITH CONVERGANCE IN'
-                    print*, 'Find_in_monotonous_1D_array', coun
+                    print*, 'Find_monotonous_LE', coun
                     write(*, '(f25.16,f25.16,f25.16,f25.16)') Value0, Array(i_cur), Array(i_1), Array(i_2)
                     pause 'STOPPED WORKING...'
                 endif
@@ -1085,6 +1091,7 @@ subroutine Find_in_monotonous_1D_array(Array, Value0, Number)
    Number = i_cur+1
 end subroutine Find_in_monotonous_1D_array
 
+
 subroutine Find_in_monotonous_2D_array(Array, Value0, Indx, Number)
    REAL(8), dimension(:,:), INTENT(in) :: Array ! in which we are looking for the Value
    REAL(8), INTENT(in) :: Value0   ! to be found in the array as near as possible
diff --git a/Source_files/Read_input_data.f90 b/Source_files/Read_input_data.f90
index 14ceeae5..dda2612e 100644
--- a/Source_files/Read_input_data.f90
+++ b/Source_files/Read_input_data.f90
@@ -4033,11 +4033,15 @@ subroutine read_DFTB_TB_Params(FN, i,j, TB_Hamil, TB_Repuls, numpar, matter, Err
    inquire(file=trim(adjustl(Folder_name)),exist=file_exist)
    if (file_exist) then ! such a file exists, use it
       File_name = trim(adjustl(Folder_name))
-   else  ! no file => assume it is a directory name, and use default file name:
-      ! Construct name of the skf file:
-      call construct_skf_filename( trim(adjustl(matter%Atoms(i)%Name)), trim(adjustl(matter%Atoms(j)%Name)), &
+   else  ! no file found:
+      File_name = trim(adjustl(m_INPUT_directory))//numpar%path_sep//trim(adjustl(Folder_name)) ! try relative path inside m_INPUT_directory
+      inquire(file=trim(adjustl(File_name)),exist=file_exist)
+      if (.not.file_exist) then ! no file either => assume it is a directory name, and use default file name:
+         ! Construct name of the skf file:
+         call construct_skf_filename( trim(adjustl(matter%Atoms(i)%Name)), trim(adjustl(matter%Atoms(j)%Name)), &
                                  File_name)    ! module "Dealing_with_DFTB"
-      File_name = trim(adjustl(Folder_name))//numpar%path_sep//trim(adjustl(File_name))
+         File_name = trim(adjustl(Folder_name))//numpar%path_sep//trim(adjustl(File_name))
+      endif
    endif
 
    ! Check if such DFTB parameterization exists:
@@ -4087,7 +4091,7 @@ subroutine read_DFTB_TB_Params_no_rep(FN, i,j, TB_Hamil, TB_Repuls, numpar, matt
    character(*), intent(out) :: Error_descript	! error save
    integer, intent(out) :: INFO	! error description
    !------------------------------------------------------
-   character(200) :: Folder_name, File_name, Inner_folder_name, path_to_skf
+   character(200) :: Folder_name, File_name, Inner_folder_name, path_to_skf, Folder_name_inner
    integer count_lines, Reason, i_cur, ind, FN_skf, ToA, N_basis_siz
    logical file_exist, file_opened, read_well
    INFO = 0
@@ -4113,7 +4117,7 @@ subroutine read_DFTB_TB_Params_no_rep(FN, i,j, TB_Hamil, TB_Repuls, numpar, matt
          goto 3426
       endif
       Folder_name = trim(adjustl(TB_Hamil(i,j)%param_name))    ! folder with chosen parameters sets
-   case default   ! it is a parameterization within the predefined directory 'DFTB'
+   case default   ! it is a parameterization within the predefined directory 'DFTB' or 'DFTB_no_repulsion'
       TB_Hamil(i,j)%param_name = trim(adjustl(path_to_skf)) ! name of the directory with skf files
       ! folder with all DFTB data:
       Folder_name = trim(adjustl(m_INPUT_directory))//numpar%path_sep//trim(adjustl(m_DFTB_norep_directory))//numpar%path_sep
@@ -4151,11 +4155,16 @@ subroutine read_DFTB_TB_Params_no_rep(FN, i,j, TB_Hamil, TB_Repuls, numpar, matt
    inquire(file=trim(adjustl(Folder_name)),exist=file_exist)
    if (file_exist) then ! such a file exists, use it
       File_name = trim(adjustl(Folder_name))
-   else  ! no file => assume it is a directory name, and use default file name:
-      ! Construct name of the skf file:
-      call construct_skf_filename( trim(adjustl(matter%Atoms(i)%Name)), trim(adjustl(matter%Atoms(j)%Name)), &
+   else  ! no file found:
+      ! Check if it is a relative path inside the INPUT_DATA directory:
+      File_name = trim(adjustl(m_INPUT_directory))//numpar%path_sep//trim(adjustl(Folder_name))
+      inquire(file=trim(adjustl(File_name)),exist=file_exist)
+      if (.not.file_exist) then ! no file either => assume it is a directory name, and use default file name:
+         ! Construct name of the skf file:
+         call construct_skf_filename( trim(adjustl(matter%Atoms(i)%Name)), trim(adjustl(matter%Atoms(j)%Name)), &
                                  File_name, '_no_repulsion')   ! module "Dealing_with_DFTB"
-      File_name = trim(adjustl(Folder_name))//numpar%path_sep//trim(adjustl(File_name))
+         File_name = trim(adjustl(Folder_name))//numpar%path_sep//trim(adjustl(File_name))
+      endif
    endif
 
    ! Check if such DFTB parameterization exists:
diff --git a/Source_files/TB_DFTB.f90 b/Source_files/TB_DFTB.f90
index 11305535..4fe5f202 100644
--- a/Source_files/TB_DFTB.f90
+++ b/Source_files/TB_DFTB.f90
@@ -243,7 +243,9 @@ function DFTB_radial_function(r_given, r_grid, param_array, ind_array, ind_inter
     if (i_array > Nsiz) then    ! return the last value
        f_out = param_array(Nsiz, ind_array)
     else
-       call linear_interpolation(r_grid, param_array(:,ind_array), r_given, f_out, i_array, x0=0.0d0, y0=0.0d0)   ! module "Little_subroutines"
+       !call linear_interpolation(r_grid, param_array(:,ind_array), r_given, f_out, i_array, x0=0.0d0, y0=0.0d0)   ! module "Little_subroutines"
+       call linear_interpolation(r_grid, param_array(:,ind_array), r_given, f_out, i_array)   ! module "Little_subroutines"
+       !print*, 'DFTB_radial_function', r_given, r_grid(i_array-1), r_grid(i_array), ':', f_out, param_array(i_array-1,ind_array), param_array(i_array,ind_array)
     endif
     nullify(dr)
 end function DFTB_radial_function
@@ -1885,7 +1887,7 @@ function DFTB_spline(a, c, R, rcut, r_dist) result (F)
       ! This works for any monotonous array:
       call Find_in_array_monoton(R, r_dist, i_array)  ! module "Little_subroutines"
       i_array = i_array - 1   ! we need floor instead of ceiling
-
+      !print*, 'DFTB_spline:', i_array, r_dist, R(i_array), R(i_array+1)
       rr0 = r_dist - R(i_array)
       rr02 = rr0 * rr0
       rr03 = rr02 * rr0
diff --git a/XTANT_3_manual.docx b/XTANT_3_manual.docx
index 6b66d7f2..90cac086 100644
Binary files a/XTANT_3_manual.docx and b/XTANT_3_manual.docx differ