[Wannier] (no subject)

[Nicola Marzari]

On 14/02/2014 06:03, Wasim Mondal wrote:
> Dear wannier90 experts,
>        My name is  wasim.  I am Ph.D student working in JNCASR, India. I
> have following two questions:
>
>
> 1. wannier function spredaing should be size of  the unit cell.
>
>            Lets I am considering a cubic unit cell having lattice
> parameter 4.00 Angstrom. I have constructed 3 t2g wannier function
> having spread 14 A^2 total spread is 42 A^2. then Is it OK?
>
>


Dear Wasim,

these look large to me - but plot them, and see if they look
good, or if they reproduce the band structure you are aiming at.

> 2. why with the increase in k-mesh wannier function spreading is changing?
>


Because spreads and centers are calculated as finite differences in
reciprocal space - the finer the sampling, the more accurate the
results. Centers converge much faster than spreads.

				nicola


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Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL