read_kappa esta.phononBag.phono3py.read_kappa ¶ ReadKappaCSV(file_path) ¶ read kappa lattice from csv file into an array of rank 2 the format of csv file is: # 8 columns: T, k_xx, k_yy, k_zz, k_xz, k_yz, k_xy, k_ave.