The ABINIT Users Mailing List ( CLOSED )

[Masayoshi Mikami <mmikami@yk.rim.or.jp>]

Hello,

Although I have NO time to try with your input, 
(and I cannot catch your point ... what is "something wrong" !?)
I may have some comments: which pseudopotentials are employed 
for La, Ga, and O ?
(That is why we cannot try with your input so easily ...
 I feel that shallow cores (5s,5p) may also be treated as 
 valence electrons for such oxide case ... I am curious ...)
The pseudopotentials you employed are reliable, indeed ?
(I do not believe that making La potential should be straightforward...)
Even if you could manage to make the potentials, 
I suspect that ecut 10 is too small for meaningful calculations 
for oxides !! 

Some literature surveys for previous calculations (oxide systems
containing La) might be helpful before you try your case, to see
which precautions should be paid for La ... 
(And some general textbooks/reviews ? )

Regards,
Masayoshi

P.S. 
Regarding how to post your questions, you might want to consult 
with the FAQ : http://www.abinit.org/ABINIT/Infos/FAQ.htm
For example, 
- I think there is a bug - making a bug report
- I didn't receive any responces to my question on ML. Why ?
- Why do my ABINIT results differ from experimental results ?


From: okuno@osa.sci.jri.co.jp
Subject: [abinit-forum] On the Lattice Optimization 
Date: Tue, 22 Jul 2003 16:31:36 +0200
Message-ID: <sympa.1058880164.10231.398@abinit.org>

> Dear all.
> 
> I am biginner to use Abinit.
> I'm first to use this mailing list, and if there are some bad-manners in 
> thie mail,
> please forgive me.
> 
> I'm now trying to lattice oprimization for distorted Perovskite material 
> LaGaO_{3} whose space 
> group number is 62(Pnma), and contains 20 atoms in unit cell.
> 
> For this purpose, I'm now using Abinit4.0 and tried it. But result is 
> something wrong.
> The calculation is very short (only two minite by 1CPU pen4) 
> and I think it must spend time for optimization.The Input file is below. 
> 
> Are there something wrong for the lattice optimization calculation for 
> LaGaO_{3}? 
> 
> Yukihiro Okuno.
> 
> # 
> ionmov 6
> dtion 100.0
> 
> 
> #Definition of the unit cell
> acell  10.365147  14.683171 10.436957
> rprim  1.0  0.0  0.0   
>        0.0  1.0  0.0   
>        0.0  0.0  1.0
> 
> #Definition of the atom types
> ntype 3           
> znucl 57 31 8  # for La, Ga, O
> 
> #Definition of the atoms
> natom 20          
> type 2 2 2 2 1 1 1 1 3 3 3 3 3 3 3 3 3 3 3 3              
> xred 
>     0.00000   0.0       0.5
>     0.50000   0.5       0.0
>     0.00000   0.5       0.5
>     0.50000   0.0       0.0
>    -0.009900  0.250    -0.002900
>     0.490100  0.250     0.502900
>     0.009900  0.750     0.002900
>     0.509900  0.750     0.497100
>     0.498000  0.250     0.060000
>     0.998000  0.250     0.440000
>    -0.498000  0.750    -0.060000
>     0.002000  0.750     0.560000
>     0.229000  0.037000  0.762000
>     0.729000  0.463000 -0.262000
>    -0.229000  0.537000 -0.762000
>     0.271000 -0.037000  1.262000
>    -0.229000 -0.037000 -0.762000
>     0.271000  0.537000  1.262000
>     0.229000  0.463000  0.762000
>     0.729000  0.037000 -0.262000
> 
> #Definition of the planewave basis set
> ecut  10.0         # Maximal kinetic energy cut-off, in Hartree
> 
> #Definition of the k-point grid
> kptopt 0
> nkpt 1 
> 
> #Definition of the SCF procedure
> nstep  70          # Maximal number of SCF cycles
> toldfe 1.0d-6     # Will stop when, twice in a row, the difference 
>                   # between two consecutive evaluations of total energy 
>                   # differ by less than toldfe (in Hartree) 
> diemac 12.0       # Although this is not mandatory, it is worth to
>                   # precondition the SCF cycle. The model dielectric
>                   # function used as the standard preconditioner
>                   # is described in the "dielng" input variable section.
>                   # Here, we follow the prescription for bulk silicon.
>