[Re:07] Regarding afm fcc-Fe convergance and higher total energy values compared to bcc fm-Fe

Posted on : November 23, 2018 (Fri) 12:48:06

by Hitoshi GOMI

Hello Qais Ali,

Thank you for the summary of the procedure.

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>Is this way of specifying the atomic positions in KKR code is correct or I need to make changes?

"0.5 0 0.7 Fe2" is okey.
But it is convenient to use the fractional coordinates.

0 0 0 Fe1
0.5 0 0.5c Fe2
0.5 0.5 0 Fe3
0 0.5 0.5c Fe4

These two methods give the same result.
The atomic positions are printed in the output as follows.

atoms in the unit cell
position= 0.00000000 0.00000000 0.00000000 type=Fe1
position= 0.50000000 0.00000000 0.70000000 type=Fe2
position= 0.50000000 0.50000000 0.00000000 type=Fe3
position= 0.00000000 0.50000000 0.70000000 type=Fe4

You can confirm.

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However, it should be noted that if you want to compare the total energy as function of c/a, you have to fix the "volume filling" of the muffin-tin sphere.
In other words, you have to calculate the muffin-tin radius for each c/a.

Regards,
Hitoshi GOMI