[QE-users] Original Symmetry Operations Not Satisfied

[Paolo Giannozzi]

On 8/19/2025 12:57 AM, TUBAI CHOWDHURY wrote:

> I try to do the geometry optimisation of Zn (001) plane,
> with a cut-off work function of 110, cut-off charge 450

if you use 440 Ry (4*wave-function cutoff, not "work function") as 
cutoff for charges, you have a single FFT grid. If you use 450 Ry, you 
have two FFT grids and additional computations. I do not see any 
advantage in using for the charge a slightly larger cutoff than the 
default (4*Ecut wfc).

> "Error in routine checkallsym (1): some of the original symmetry operations not satisfied"

if you set constraints on atomic positions, you have to ensure that they 
do not break the symmetry. Your constraints do. Presumably you should 
replace "0 0 0" below with "1 1 0", that is: keep z coordinate fixed, 
leave x and y free

> ATOMIC_POSITIONS {angstrom}
> Zn      1.307180   0.754701  22.436581
> Zn     -0.000000   1.509401  20.000000  0 0 0
> Zn      0.000000   3.018803  22.436581
> Zn     -1.307180   3.773503  20.000000  0 0 0
> Zn      3.921540   0.754701  22.436581
> Zn      2.614360   1.509401  20.000000  0 0 0
> Zn      2.614360   3.018803  22.436581
> Zn      1.307180   3.773503  20.000000  0 0 0

-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216

-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216