[Pw_forum] vc-relax question

[Paolo Giannozzi]

On Wed, 2014-11-26 at 15:58 +0000, Samin, Adib J. wrote:

> I am trying to run a test simulation on the silicon unit cell using
> vc-relax. When I run the simulation using "ibrav=2" the simulation
> converges in 4 scf cycles. However, when I attempt to run the
> simulation using "ibrav = 0" it doesn't converge in 18 scf cycles.

simplest explanation: the two structures are not the same

P.

-- 
 Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
 Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
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