[Pw_forum] strange bandstructure

[Gabriele Sclauzero]

Lex Kemper wrote:
> Hi idoldog,
> 
> I presume what you're referring to as 'strange' is the lines jumping
> from one band to another. This is, as I understand it, the bands.x code
> not seeing enough overlap between the kpoints to order them properly.
> There are two ways to fix this:
> 
> (a) Run with more points per line in k-space
> (b) If you're only interested in a few bands, fix them by hand.
> 
> Good luck!
> 
> Lex Kemper
> University of Florida

If there is this kind of problem with bands.x, you can do as Lex correctly suggested, or 
try to upgrade to the latest espresso versions, which should use a symmetry-based analisys 
rather than the overlap-based one (eventually enabled with lsym=.TRUE., actually much more 
computationally expensive... but if you really want nice bands labeled by symmetry that's 
the price you'll have to pay ;-)

HTH

GS


> 
> idoldog wrote:
>> Dear PWSCF user,
>>  
>> I just finished a bandstructure calculation about semiconductor SrTiO3. I get a strange bandstructure.
>>  
>> In order to see clearly, I redraw the graph and mark same bands, which may be wrong, with different colors.
>>  
>> Some friends tell me it would be better without lines.  Another friends tell me to change the path of markde lines.
>>  
>> I want to know that whether these bands are correct and if they are wrong, where my mistakes are and how to solve them.
>>  
>> The server blocked my files attched, so please visit 
>> graph with colorful lines:http://pic.emuch.net/200903/04/33e7b7b230bfd248104b8ba1ada65361.jpg
>> graph without line:http://pic.emuch.net/200903/04/4a2fdd6cbf9f7d0ce2df725c579e57ea.jpg
>>
>> If you couldn't visit them successfully, mail me. 
>>  
>> I need your help.
>>  
>> all the best.  
>>  
>> Li Fei
>> 2009-03-04
>>
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