code: def read_cyc(this, fn, conv=1.0):
      
      f = paropen(fn, "r")
      f.readline()
      f.readline()
      f.readline()
      f.readline()
      cell = np.array( [ [ 0.0, 0.0, 0.0 ], [ 0.0, 0.0, 0.0 ], [ 0.0, 0.0, 0.0 ] ] )
      l = f.readline()
      s = map(float, l.split())
      cell[0, 0] = s[0]*conv
      cell[1, 0] = s[1]*conv
      cell[2, 0] = s[2]*conv
      l = f.readline()
      s = map(float, l.split())
      cell[0, 1] = s[0]*conv
      cell[1, 1] = s[1]*conv
      cell[2, 1] = s[2]*conv
      l = f.readline()
      s = map(float, l.split())
      cell[0, 2] = s[0]*conv
      cell[1, 2] = s[1]*conv
      cell[2, 2] = s[2]*conv
      this.set_cell(cell)
      this.set_pbc(True)
      f.close()
docs: Read the lattice information from a cyc.dat file (i.e., tblmd input file)