Dear experts, The Nominal charge of Ba, Ti and O are 2, 4 and -2 respectively. But using Born effective charge, for Ba, Ti and O are 2.77, 7.25, -2.15, 5.71. how to get these values using vasp? what are INCAR tags should I use? what is the meaning of two oxygen here? ( from BaTiO3, one Ba, one Ti, three oxygen) (I attached the screenshot of BaTiO3) Thanks in advance