[QE-users] Error in electronic band structure calculation VCA vs substitution

[Soumyadeep]

Dear All,
    I am performing a electronic band structure calculation of NaFeAs 
with VCA and atomic substitution. VCA was done using 
upftools/virtual_v2.x with 50% Cu doping at Fe site to make 
NaFe0.5Cu0.5As.

   In atomic substitution method I replace one Fe atom by Cu to make 
NaFe0.5Cu0.5As (two Fe atom in primitive cell in parent compound). I 
have used same pseudopotential file for VCA and all other calculation 
parameters are also same. All the structures are also geometry 
optimized. But electronic band structure is different (attached)? Though 
total number of bands is same.

   Kindly point out my mistakes?

with many thanks and best regards
Soumyadeep
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Soumyadeep Ghosh,
Senior Research Fellow,
Homi Bhabha National Institute (HBNI),
Raja Ramanna Centre for Advanced Technology, Indore, India-452013
Mob: (+91)9424664553
User Lab: 0731244-2580
Email: soumyadeepghosh35 at gmail.com, soumyadeep at rrcat.gov.in
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