I would like to perform a DFT+U calculation on transition metal oxides using CASTEP.
To learn about the method, I tried some simple calculations that are published in the literature about doped TiO2. I have set up the model, giving U a value for the transition metals in the cell, and calculated CATEP with LDA+U checked.
The result I got was a closed shell result for a couple of U value choices, while I was expecting some unpaired spin appear (as predicted by the papers I try to reproduce).
Is that a problem with the choice of U? Does CASTEP automatically convert the result closed shell (showing only one DOS during analysis) when up and down spin space has the same DOS?
To learn about the method, I tried some simple calculations that are published in the literature about doped TiO2. I have set up the model, giving U a value for the transition metals in the cell, and calculated CATEP with LDA+U checked.
The result I got was a closed shell result for a couple of U value choices, while I was expecting some unpaired spin appear (as predicted by the papers I try to reproduce).
Is that a problem with the choice of U? Does CASTEP automatically convert the result closed shell (showing only one DOS during analysis) when up and down spin space has the same DOS?
