[QE-users] Error in routine smallgk (1): Not a group

[Paolo Giannozzi]

This kind of problems invariably arises when the system has symmetries 
but the structure that is passed is not perfectly symmetric (typically: 
ibrav=0 user-defined lattice vectors and/or atomic coordinates with few 
correct significant figures). Some codes may have different ideas on the 
symmetry of the system.

By the way: setting the lattice parameter to the Bohr-Angstrom 
conversion factor is not a good idea. The lattice parameter is the 
lattice parameter, not something else.

Paolo

On 18/01/2025 13:47, jkmodi22 at iitk.ac.in wrote:

> Dear QE users,
> 
> I get an error " Error in routine smallgk (1):
>                   Not a group"
> while running bands.x.  How to resolve this error? What is the cause of
> this error?
> 
> I am sharing my scf.in file :
> 
> &CONTROL
> calculation = 'scf'
> prefix = 'GaS-GaSe'
> pseudo_dir = '/hpc/phd/jkmodi22/pseudopot//',
> tefield=.false. ,
> dipfield=.false. ,
> outdir = './output/'
> disk_io = 'low'
> tprnfor=.true.
> tstress=.true.
> /
> &SYSTEM
> ibrav=0
> celldm(1)=1.889725989
> nat= 8
> ntyp= 3
> ecutwfc= 50
> ecutrho= 500
> vdw_corr=dft-d
> occupations='smearing'
> degauss=0.01
> smearing='gaussian'
> edir = 3
> emaxpos = 0.9
> eopreg = 0.1
> eamp = 0
> /
> &ELECTRONS
> conv_thr    = 1.D-8
> mixing_beta = 0.5D0
> /
> K_POINTS automatic
> 12 12 1 0 0 0
> ATOMIC_SPECIES
> Ga    1.0 Ga.pbe-dn-kjpaw_psl.0.2.UPF
> S    1.0 S.pbe-n-kjpaw_psl.0.1.UPF
> Se    1.0 Se.pbe-n-kjpaw_psl.0.2.UPF
> CELL_PARAMETERS (alat=  1.88972599)
>     3.659276963  -0.000000000   0.000000000
>    -1.829638481   3.169026809   0.000000000
>     0.000000000   0.000000000  20.000000000
> ATOMIC_POSITIONS (crystal)
> Ga       1.000000000  -0.000000000   0.755828781
> Ga       1.000000000   0.000000000   0.633658430
> S        0.666666666   0.333333333   0.808945247
> S        0.666666666   0.333333333   0.580641199
> Ga       0.666666666   0.333333333   0.361551443
> Ga       0.666666666   0.333333333   0.240133348
> Se       0.333333333   0.666666666   0.423359226
> Se       0.333333333   0.666666666   0.178282326
> 
> 
> 
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-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216