formation energy and cohesive energy

[IBRAHIM]

Dear All,

For large supercell, I use single k-point.

To have all energy values on the same level of accuracy for formation energy and cohesive energy calculations.
Can I use converged parameters (Encut, K-point, ..) for the sub-systems? or have to be done on single k-point?

Many thanks in advance,
Best regards,
Ibrahim

[IBRAHIM]

Dear ALl,

For large supercell, I use single k-point.

To have all energy values on the same level of accuracy for formation energy and cohesive energy calculations.
Should I use converged parameters (Encut, K-point, ..) for the sub-systems? or have to be done on single k-point and the same Encut?

I appreciate your recommendation, in advance.

Best regards,
Ibrahim

[tfrankcombe]

What's the "sub system"?

You should consider how the errors in your energies due to finite sampling and cutoffs etc propagate through your cohesive energy calculation.