### Optimization of tetragonal perovskit???

Posted:

**Mon Feb 24, 2020 11:47 am**Dear all

Greetings

I am trying to do optimization for tetragonal phase of a perovskite specifically CsPbCl3

I give spgroup input variable which 140 due to papers but my run stops and gives me the following error:

--- !ERROR

src_file: symatm.F90

src_line: 201

mpi_rank: 13

message: |

Largest error (above) is so large (0.01) that either input atomic coordinates (xred)

are wrong or space group symmetry data is wrong.

Action : correct your input file.

By the way atomic coordinates are correct and I try in reduced and in angstrom coordinates...

I have tries to give nsym and symrel, the structure turns to cubic

here is my input

ndtset 2

#Definition of the atomic positions without relaxing the lattice parameters and fixed Pb

optcell1 0

ionmov1 2

#Definition of the basis of the geometry determined by dataset 1 (so using getxcart 1)

getxcart2 1

optcell2 3

ionmov2 2

dilatmx2 1.5

ecutsm2 0.5

# COMMON INPUT DATA

#Definition of the unit cell

acell 5.64 5.64 5.77 Angstr

#rprim 1.0 0.0 0.0

0.0 1.0 0.0

0.0 0.0 1.0

#Definition of the atom types

ntypat 3

znucl 55 82 17

#Definition of the atoms

natom 5

typat 1 2 3 3 3

xred 0.0 0.0 0.0

0.5 0.5 0.5

0.5 0.5 0.0

0.5 0.0 0.5

0.0 0.5 0.5

#xangst

0.0 0.0 0.0

2.82 2.82 2.885

2.82 2.82 0.0

0.0 2.82 2.885

2.82 0.0 2.885

#Definition of the planewave basis set

ecut 45.0

# find the optimal total energy

ntime 200

tolmxf 1.0d-5

toldff 1.0d-6

nband 40

spgroup 140

brvltt -1

chksymbreak 0

chkprim 0

#Definition of the k-point grid

kptopt 1

ngkpt 4 4 4

nshiftk 1

shiftk

0.5 0.5 0.5

getwfk -1

prtcif 1

prtgeo 1

#Definition of the SCF procedure

nstep 100

#toldfe 1.0d-6

diemac 12.0

Regards

Nawzad

Greetings

I am trying to do optimization for tetragonal phase of a perovskite specifically CsPbCl3

I give spgroup input variable which 140 due to papers but my run stops and gives me the following error:

--- !ERROR

src_file: symatm.F90

src_line: 201

mpi_rank: 13

message: |

Largest error (above) is so large (0.01) that either input atomic coordinates (xred)

are wrong or space group symmetry data is wrong.

Action : correct your input file.

By the way atomic coordinates are correct and I try in reduced and in angstrom coordinates...

I have tries to give nsym and symrel, the structure turns to cubic

here is my input

ndtset 2

#Definition of the atomic positions without relaxing the lattice parameters and fixed Pb

optcell1 0

ionmov1 2

#Definition of the basis of the geometry determined by dataset 1 (so using getxcart 1)

getxcart2 1

optcell2 3

ionmov2 2

dilatmx2 1.5

ecutsm2 0.5

# COMMON INPUT DATA

#Definition of the unit cell

acell 5.64 5.64 5.77 Angstr

#rprim 1.0 0.0 0.0

0.0 1.0 0.0

0.0 0.0 1.0

#Definition of the atom types

ntypat 3

znucl 55 82 17

#Definition of the atoms

natom 5

typat 1 2 3 3 3

xred 0.0 0.0 0.0

0.5 0.5 0.5

0.5 0.5 0.0

0.5 0.0 0.5

0.0 0.5 0.5

#xangst

0.0 0.0 0.0

2.82 2.82 2.885

2.82 2.82 0.0

0.0 2.82 2.885

2.82 0.0 2.885

#Definition of the planewave basis set

ecut 45.0

# find the optimal total energy

ntime 200

tolmxf 1.0d-5

toldff 1.0d-6

nband 40

spgroup 140

brvltt -1

chksymbreak 0

chkprim 0

#Definition of the k-point grid

kptopt 1

ngkpt 4 4 4

nshiftk 1

shiftk

0.5 0.5 0.5

getwfk -1

prtcif 1

prtgeo 1

#Definition of the SCF procedure

nstep 100

#toldfe 1.0d-6

diemac 12.0

Regards

Nawzad