I have been trying to get reasonably accurate values for oxidation states and ionic radii for ions in transition metal sulfide materials from their VASP outputs. I tried using the bader charge analysis code on the CHGCAR file (by summing up AECCAR0 and AECCAR2 files). The ionic radii calculated from the atomic volumes given in the AVF.dat file is not giving the radii values as expected (Au+ is larger than S2- according to the analysis). Also, kindly suggest how can I determine the oxidation states of the metal ions from the bader charges on each atom.
Choose -b weight to calculate the integeration of atom charges, which is more accurate.
Wang Jinkai Thank you for your answer. I'm assuming we need to look at the ACF.dat file after choosing the -b weight. Since the bader charges are basically the number of electrons, shouldn't it be close to an integer as oxidation states should also be integers? Also, is calculating the ionic radii from the atomic volumes given in it reliable?
In VASP based on DFT, charge is distributed in the 3D space.
Diving charges to a certain atom is a man-defined thing in chemistry and is difficult.
Bader charge (and other charge like muillken charge or hirsffeld charge) is just one of the ways to divide the charges.
And the divided charges of a atom is not essential to suit the man-defined oxidation state like your situation.
Maybe you could use ORCA or other quantum chemistry softwares based on basis not plane wave function. Or just accept the result if all your calculation process and paramters are correct.
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