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[<6671011@163.com>]

Dear Emmanuel,

Though it speeds up the calculation a lot, I will not "perform an internal
relaxation before relaxing the box". According to my experiences in Carbon
Nanotubes, sometimes they do give the same results---which could be a disaster
if one cares about the energy.

Sincerely,
Guangfu Luo



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What about warnings?
You use occopt 3 but you don't specify nband. Are you sure that makes no
problem? Is it a metal? An insulator? 
toldfe e-6 is a bit low... e-8 should be better.
Maybe you should perform an internal relaxation before relaxing the box.

Emmanuel ARRAS


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dsagfds a écrit :

Dear abinit users,

I am trying to calculate the optimized acell of Phase-change material
Ge1Sb2Te4,which is widely used in the optical storage apeplication.The
supercell in the calculation is formed by 8*Ge1Sb2Te4.I am sure there is
nothing wrong with my model, so there must be something wrong in other
parameters.When I run the relaxation, I found strong discontinuities in acell,
#####################################################
acell= 2.2000000000E+01 2.2000000000E+01 2.2000000000E+01
acell= 2.2000000000E+01 2.2000000000E+01 2.2000000000E+01
acell= 2.2218736471E+01 2.2215964594E+01 2.2218447042E+01
acell= 2.2218736471E+01 2.2215964594E+01 2.2218447042E+01
acell= 2.5092656679E+01 2.5051982098E+01 2.5086577317E+01
acell= 2.5092656679E+01 2.5051982098E+01 2.5086577317E+01
acell= 2.3329634141E+01 2.3311234526E+01 2.3327636658E+01
######################################################
After a day long's calculation, the computation stoped eventually with
following indication

scfcge : ERROR -
Potential-based CG line minimization not converged after 13 restarts.
Action : read the eventual warnings about lack of convergence.

You will find in the present mail my input and also the results of the
calculations.
Is my input wrong ? Thanks a lot to help me if someone has a good idea.

Sincerely yours,
dsagfds


Here is my input file
#Definition of the unit cell
acell 3*22.0000000000 rprim 1.000000000000 0.000000000000 0.000000000000 
0.000000000000 1.000000000000 0.000000000000
0.000000000000 0.000000000000 1.000000000000
#definition of relaxation
optcell 2
ionmov 3
ntime 40
dilatmx 1.4
ecutsm 0.6
ortalg 2
prtcml 1
prtvol 10

#definition of k grids
kptopt 1
ngkpt 2 2 2

#definition of atoms
ntypat 3 znucl 51 32 52 natom 56 typat 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
3 3 3 3 3 3 3 3 3 3 3 3 1 2 1 2 1 
1 2 1 1 1 2 1 2 1 1 2 1 1 1 2 1 1 1 2 xred 0.500000000000 0.000000000000
0.000000000000 0.750000000000 0.250000000000 0.000000000000 0.750000000000
0.000000000000 0.250000000000 0.000000000000 0.000000000000 0.000000000000
0.250000000000 0.250000000000 0.000000000000 0.500000000000 0.500000000000
0.000000000000 0.750000000000 0.750000000000 0.000000000000 0.250000000000
0.000000000000 0.250000000000 0.500000000000 0.250000000000 0.250000000000
0.750000000000 0.500000000000 0.250000000000 0.500000000000 0.000000000000
0.500000000000 0.750000000000 0.250000000000 0.500000000000 0.750000000000
0.000000000000 0.750000000000 0.000000000000 0.500000000000 0.000000000000
0.250000000000 0.750000000000 0.000000000000 0.000000000000 0.250000000000
0.250000000000 0.250000000000 0.500000000000 0.250000000000 0.500000000000
0.750000000000 0.250000000000 0.000000000000 0.000000000000 0.500000000000
0.250000000000 0.250000000000 0.500000000000 0.500000000000 0.500000000000
0.500000000000 0.750000000000 0.750000000000 0.500000000000 0.250000000000
0.000000000000 0.750000000000 0.500000000000 0.250000000000 0.750000000000
0.750000000000 0.500000000000 0.750000000000 0.000000000000 0.750000000000
0.250000000000 0.000000000000 0.500000000000 0.500000000000 0.250000000000
0.750000000000 0.500000000000 0.000000000000 0.250000000000 0.750000000000
0.250000000000 0.500000000000 0.750000000000 0.500000000000 0.750000000000
0.750000000000 0.000000000000 0.750000000000 0.750000000000 1.000000000000
0.500000000000 0.250000000000 1.000000000000 0.250000000000 0.500000000000
0.250000000000 0.250000000000 0.250000000000 0.500000000000 0.500000000000
0.250000000000 0.750000000000 0.750000000000 0.250000000000 1.000000000000
1.000000000000 0.250000000000 0.500000000000 0.250000000000 0.500000000000
1.000000000000 0.750000000000 0.500000000000 0.750000000000 0.250000000000
0.750000000000 1.000000000000 0.250000000000 1.000000000000 0.250000000000
0.750000000000 0.250000000000 0.500000000000 1.000000000000 0.250000000000
0.250000000000 0.500000000000 0.500000000000 0.750000000000 1.000000000000
0.500000000000 0.250000000000 0.250000000000 0.750000000000 0.750000000000
0.750000000000 0.750000000000 1.000000000000 1.000000000000 0.750000000000
0.500000000000 0.250000000000 1.000000000000 1.000000000000 0.750000000000
1.000000000000 0.250000000000 1.000000000000 0.500000000000 0.250000000000
0.750000000000 0.750000000000 0.250000000000 0.500000000000 1.000000000000
0.500000000000 0.750000000000 1.000000000000 0.750000000000 1.000000000000
1.000000000000 
# definiton of scf process
iscf 5
nstep 80
diemac 500
occopt 3
enunit 2 tsmear 0.04 ecut 10 toldfe 1.0d-6