[QE-users] relax calculation on MD snapshots

[Giuseppe Mattioli]

Dear Chirantan
As detailed in thousands of previous posts, it is totally useless to  
say "it does not converge" without providing all the details (input,  
output, QE version, pseudopotentials,...)
HTH
Giuseppe

Quoting Chirantan Pramanik <chirantan.pramanik at weizmann.ac.il>:

> Hello,
>
> I need to calculate phonon for some structures of Mg in water  
> obtained from MD simulations. I ran AIMD at 300K and performed 16000  
> steps with 1 fs time step. Then, I collected equidistant snapshots  
> from the temperature-stabilized region to compute phonon. However,  
> according to a few previous studies, they optimized all atomic  
> coordinates of the MD snapshots to get the reliable phonon required  
> for isotopic study. When I try to optimize, the structures never  
> converge. I tried using more steps and lower thresholds. But does  
> not work. Please help to solve this. Also, as the Mg ion resides in  
> the same water cage at this time, should most of the snapshots give  
> the same optimized structure?
>
> Regards,
> Chirantan
>
>
>
>
> Chirantan Pramanik
> Postdoctoral Researcher
> Dept. of Earth and Planetary Sciences
> Weizmann Institute of Science
> Rehovot, Israel



GIUSEPPE MATTIOLI
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
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E-mail: <giuseppe.mattioli at ism.cnr.it>