Regarding Warnings under PBC Conditions with SCCS

Soma

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Nov 20, 2025, 11:10:55 AMNov 20

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Structural optimization of a metal-organic frame slab was performed under a static electric field and PBC using the implicit solvent effect (SCCS).

Before SCCS was used, there were no warnings, but after SCCS was used, the following warnings appeared.

"WARNING in qs_sccs.F:207 :: The stress tensor for SCCS has not yet been fully validated"

"WARNING in qs_sccs.F:489 :: The system (solute) has a non-negligible charge of +.000074. It is recommended to use non-periodic boundary conditions (PERIODIC none) combined with an appropriate Poisson solver (POISSON_SOLVER MT or analytic)"

I guess GEO_OPT and SCCS don't involve tensor calculations, so the first warning can be ignored, but what do you think?

I would like to resolve the above two warnings while keeping PBC condition.

I'd appreciate your advice.

UiO-66-H_2layer_optimized.xyz

UiO-66-H_2layer_Add_SCCS_3rd.out.zip

UiO-66-H_2layer_Add_SCCS.inp

Krack, Matthias

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Nov 20, 2025, 11:27:34 AMNov 20

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Hi

Your EPS_DEFAULT value is with 1.0E-7 way too large which causes a bad electron count and thus the non-negligible system charge. An EPS_DEFAULT value of 1.0E-12 would be more appropriate.

You request in your input explicitly the calculation of the stress tensor (STRESS_TENSOR analytical) which causes the warning though you are performing a GEO_OPT run.

HTH

Matthias

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Soma

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Nov 21, 2025, 5:23:07 AMNov 21

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Dear Matthias,

Thank you for your reply.

I will try to remove STRESS_TENSOR analytical and use EPS_DEFAULT value of 1.0E-12.