Hello All,
I've been facing difficulty in executing geometry optimization of a sodium polyanionic phosphate (Na4Fe3P4O15) crystal in CASTEP (please find the input and output files attached). When I plot the pressure and energy (see P&E.PNG), the simulation seems to be moving in the right direction. However, I eventually hit the limit for max_scf_cycles which is currently set to 500 and the optimization exits. What can be done? Some other details about the simulation are as follows:
1. I've set 'spin_polarized : true' and 'spin : 48' (There are 12 Fe atoms).
2. Hubbard-type correction U was set to 4.3 eV for Fe atoms.
Any tips would be helpful.
Thanks,
Amith Adoor
hi Amith Adoor Cheenady ,
I have read these files. I found that your system is extremely complex with large cell, spin of Fe and +U.
In my experience, I often do simple calculation for these complex system. For example, optimization starts from no spin and no U calculation. And then optimize with spin, after that with U. This may be safer to get convergence.
Wang Jinkai. Thank you! I will try increasing the complexity of the calculation more gradually.
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