[Pw_forum] reusing converged density

[Paolo Giannozzi]

Luke Shulenburger wrote:

> I would like to calculate the ground state of a system with several 
> different strains.  As the calculations are somewhat hard to converge,
> I was hoping that I could re-use the density and wavefunctions from
> one of the calculations as starting points of the others.

you can, but with some (serious) limitations. Basically, restarting
from the charge density of previous calculations works only if both
the cell and the cutoff for the charge density of the two calculations
are the same; restarting from previously calculated orbitals works only
if the cell, the cutoff for the orbitals, and the k-points of the two
calculations are the same. Some of these restrictions may be easy to
lift, other are not so easy

P.
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy