WAVELET Poisson solver not implemented for XY periodicity in CP2K 2026.1

[mark]

Dear CP2K developers and users,

I am studying a two-dimensional system consisting of a slab with an adsorbed molecule. For this reason, I would like to use two-dimensional periodic boundary conditions in the (xy) plane together with the WAVELET Poisson solver.

The relevant sections of my input file are:

&POISSON PERIODIC XY 

  POISSON_SOLVER WAVELET 

&END POISSON

and

&SUBSYS 

 &CELL 

 A 19.497000000000 0.000000000000 0.000000000000 

 B -9.748500000000 16.884897297585 0.000000000000 

 C 0.000000000000 0.000000000000 48.982084201000 

 PERIODIC XY 

 &END CELL

However, the calculation stops with the following error:

******************************************************************************* * ___ * * / \ * * [ABORT] * * \___/ Poisson solver for this periodicity not yet implemented * * | * * O/| * * /| | * * / \ pw_poisson_read_input.F:160 * ******************************************************************************* ===== Routine Calling Stack ===== 5 pw_env_rebuild 4 qs_env_rebuild_pw_env 3 qs_env_setup 2 qs_init_subsys 1 CP2K

I am using CP2K version 2026.1.

Is the WAVELET Poisson solver expected to support PERIODIC XY, or is it currently limited to other periodicity settings? If this combination is not implemented, what would be the recommended approach for treating a slab with an adsorbed molecule using two-dimensional periodic boundary conditions? I would like to avoid face this problem with XYZ periodicity + dipole correction.

I have attached the complete input file for reference.

Thank you very much in advance for your help.

Best regards,
Marco

[Fabian Ducry]

Dear Marco,

in the 2026.2 version xy periodicity is implemented for the wavelet solver. Alternatively, you can rotate the coordinates and use periodicity xz with version 2026.1

Cheers,
Fabian

[mark]

Dear Fabian,

thank you for your help

Cheers,

Marco