code: def read_nmr_efg_tensor(self):
          
  
          header_pattern = r'Electric field gradients \(V/A\^2\)\n' \
                           r'-*\n' \
                           r' ion\s+V_xx\s+V_yy\s+V_zz\s+V_xy\s+V_xz\s+V_yz\n' \
                           r'-*\n'
  
          row_pattern = r'\d+\s+([-\d\.]+)\s+([-\d\.]+)\s+([-\d\.]+)\s+([-\d\.]+)\s+([-\d\.]+)\s+([-\d\.]+)'
          footer_pattern = r'-*\n'
  
          data = self.read_table_pattern(header_pattern, row_pattern, footer_pattern, postprocess=float)
          tensors = [make_symmetric_matrix_from_upper_tri(d) for d in data]
          self.data["unsym_efg_tensor"] = tensors
          return tensors
docs: Parses the NMR Electric Field Gradient Raw Tensors
  
          Returns:
              A list of Electric Field Gradient Tensors in the order of Atoms from OUTCAR