[Wien] Formula to calculate Lattice Constant and angle of BiFeO3

[delamora]

Yes, in the WIEN2k you find a, b and c optimization all set for you, but ti include the angles the number of structures would increase exponentially;

1 dimension    n

2 dimensions    n**2

3 dimensions    n**3

4 dimensions    n**4

5 dimensions    n**5

6 dimensions    n**6


4**6=4096


So you must do each optimization separately

First you optimize a, b, c

then you vary alpha and optimize, then beta and finally gamma


then you return to the beginning;

optimize a, b and c

until the changes in the cell parameters change little.


________________________________
De: wien-bounces at zeus.theochem.tuwien.ac.at <wien-bounces at zeus.theochem.tuwien.ac.at> en nombre de Mian Fayyaz Ahmad <fayyaz.pc at gmail.com>
Enviado: domingo, 22 de junio de 2014 09:41 p.m.
Para: Wien at zeus.theochem.tuwien.ac.at
Asunto: [Wien] Formula to calculate Lattice Constant and angle of BiFeO3


Respected, Wien2K Community
   I want to calculate Lattice Constant and angle of BiFeO3 in space group P1( Triclinic ). I have done volume optimization. I found a formula [V = abc( 1?cos**2alpha ?cos**2beta? cos**2gamma+2*cos alpha*cos beta*cos gamma)**1/2]. I found only volume in volume optimization. How can i found lattice parameters a, b , c and angles???
please help me in this regard.
thanks in advance
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