[Wannier] Error in allocating wann_func in plot_wannier

Jonathan Yates jonathan.yates at materials.ox.ac.uk
Wed Jul 29 11:47:11 CEST 2009

On 29 Jul 2009, at 09:34, Sumanta Bhandary wrote:

> Dear W90 users,
>               I am new to wannier and trying to do parallel
> calculation . But the calculation stops saying ""Error in allocating
> wann_func in plot_wannier" . Could you please give me any suggestion ?

Dear Sumanta,

Firstly, wannier90 is not a parallel program. It is fine to run your  
original ab-initio program in parallel - but then you should run  
wannier90 in serial.

The error message means the program is running out of RAM when it  
tries to form the wannier functions on a regular grid for plotting.  
There are various things that can reduce the memory (actually, try  
running in serial first - that could be the problem).

1- The size of the grid. An important keyword is  
wannier_plot_supercell. The userguide and tutorial will explain this.
If you're using pw2wannier90 (ie QE) then there is a logical flag  
reduce_unk which reduces the density of the grid by half (so memory by  

2- The number of wannier functions to plot at one time. By default we  
plot all of them. Use wannier_plot_list to plot a subset.


Department of Materials, University of Oxford, Parks Road, Oxford, OX1  
tel: +44 (0)1865 283225                http://users.ox.ac.uk/~oums0549/

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