<s>
The	O
FLEUR	B-Application
code	O
(	O
also	O
Fleur	B-Application
or	O
fleur	B-Application
)	O
is	O
an	O
open-source	O
scientific	O
software	O
package	O
for	O
the	O
simulation	O
of	O
material	O
properties	O
of	O
crystalline	O
solids	O
,	O
thin	O
films	O
,	O
and	O
surfaces	O
.	O
</s>
<s>
The	O
physical	O
model	O
used	O
in	O
Fleur	B-Application
simulations	O
is	O
based	O
on	O
the	O
(	O
F	O
)	O
LAPW( +LO	O
)	O
method	O
,	O
but	O
it	O
is	O
also	O
possible	O
to	O
make	O
use	O
of	O
an	O
APW+lo	O
description	O
.	O
</s>
<s>
For	O
the	O
description	O
of	O
the	O
exchange-correlation	O
functional	O
different	O
parametrizations	O
for	O
the	O
local	O
density	O
approximation	O
,	O
several	O
generalized-gradient	O
approximations	O
,	O
Hybrid	O
functionals	O
,	O
and	O
partial	O
support	O
for	O
the	O
library	O
are	O
implemented	O
.	O
</s>
<s>
The	O
Fleur	B-Application
code	O
can	O
be	O
used	O
to	O
directly	O
calculate	O
many	O
different	O
material	O
properties	O
.	O
</s>
<s>
For	O
the	O
calculation	O
of	O
optical	O
properties	O
Fleur	B-Application
can	O
be	O
combined	O
with	O
the	O
Spex	O
code	O
to	O
perform	O
calculations	O
employing	O
the	O
GW	O
approximation	O
to	O
many-body	O
perturbation	O
theory	O
.	O
</s>
