The ABINIT Users Mailing List ( CLOSED )

[santosh_bobade@yahoo.com]

Dear Abinit user

I am trying to know more about code so that it can be really 
exploited for. while doing this I am trying to run some response function
calculation for BaTiO3 to find out whether I can match mine with reported 
value.  
Here is detail what exactly the Problem is

spgroup 123 
                  
Ba 0.0 0 0 0.0                    Ba 0.0 0 0 0.0
Ti 0.5 0.5 0.5                    Ti 0.5 0.5 0.5
O1 0.5 0.5 0.0                    O1 0.5 0.5 0.0
O2 0.5 0.0 0.5                    O2 0.5 0.0 0.5
                                  O3 0.0 0.5 0.5

natom 4                            natom 5
typat 1 2 3 3                      typat 1 2 3 3 3 
ETOT -55.*****                    -68.******
ecut 40
kptopt 1                           kptopt 1
nkpt 10                            nkpt 10
kptrlen 45                         kptrlen 45
In both cases lattice constants are same. and other inputs are also same.
The difference is in first case I used spacegroup and in later atomic 
cordinates
are explicitely provided.

Now what I found the Total Energy is different although the case in which 
coordinates were input, predicts same space group ie 123.

The only thing that bothers me the energy difference  
i used a=b=3.98, c=4.03 and ecut =40 for both run
can anybody throw light on this aspect?

Now I think, This will make my case.
Thank for reply.

With Regards
Santosh Bobade