ABINIT Discussion Forums

Hello there,
I wanted to optimize the geometry of unit cell but not that of primitive cell.the in files was as following,

Structural optimisation

#Common input data
chksymbreak 0
#Definition of the unit cell
#**********************************
acell 14.9233111129 14.9233111129 12.7690025567
angdeg 90 90 120
chkprim 0
#Definition of the atoms
#*********************
spgroup ***
ntypat 3
znucl A B C
natom 11
brvltt -1
natrd 5
typat 1 2 3 3 3
xred 0.796740 0.203260 0.744830
0.000000 0.000000 0.000000
0.000000 0.000000 0.234010
0.540530 0.459470 0.849360
0.560330 0.439670 0.272960
...

In the out file the result were as followings,

-outvars: echo values of variables after computation --------
acell 9.3082927224E+00 9.3082927224E+00 9.3082927224E+00 Bohr
amu 2A 2B 2C
chksymbreak 0
dilatmx 1.05000000E+00
ecut 7.00000000E+01 Hartree
ecutsm 1.40000000E+01 Hartree
...
optcell 2
rprim 7.7866284655E-01 4.4956120406E-01 4.3769726433E-01
-7.7866284655E-01 4.4956120406E-01 4.3769726433E-01
-2.2038842239E-16 -8.9912240813E-01 4.3769726433E-01
...

why ?
But it will not run if I delete "brvltt" and "spgroup". How can I do for optimizition the unit cell?

In addition, Whether we have the same result, utilizing abinit in windows system and in Linux system, or not?
Thank you!
Best wishes！
nannan

You can't optimize the conventional cell but not the primitive cell, they're different representations of the same thing. It's always preferable to work with the primitive cell because it's so much smaller. And, abinit will give the same answers on Windows as on Linux (it's just a different representation of the same thing posting.php?mode=reply&f=8&t=2056#

jzwanzig wrote:You can't optimize the conventional cell but not the primitive cell, they're different representations of the same thing. It's always preferable to work with the primitive cell because it's so much smaller. And, abinit will give the same answers on Windows as on Linux (it's just a different representation of the same thing posting.php?mode=reply&f=8&t=2056#

Thanks for your reply. It is the real answer I want. Thanks again!