Feature: periodic self-consistent continuum solvation (SCCS) Step2: SCCS with PCC 0D/2D by LKFEIYI · Pull Request #8194 · deepmodeling/abacus-develop

LKFEIYI · 2026-10-21T02:21:27Z

Reminder

I have read AGENTS.md and docs/developers_guide/agent_governance.md.
I have linked an issue or explained why this PR does not need one.
I have added adequate unit tests and/or case tests, or explained why not.
I have listed the exact verification commands run and their results.
I have described user-visible behavior changes, including INPUT parameter changes.
I have explained core-module impact for ESolver, HSolver, ElecState, Hamilt, Operator, Psi, or other source/ changes.
I have requested any needed governance exception below.

Linked Issue

Third part of #8052. It follows #8075 (PCC) and #8162 (SCCS Step 1: periodic SCCS).

Remaining follow-up PRs, each stacked on the previous one: lowpass and full cavity → SCF integration → solvent-aware cavity.

What's changed?

imp_sol 2 can now be combined with assume_isolated pcc_0d and pcc_2d (O. Andreussi and N. Marzari, Phys. Rev. B 90, 245101 (2014)). This removes the cell-size dependence of charged solvated systems: molecules (pcc_0d) and slabs (pcc_2d, open along pcc_2d_axis). Neutral periodic SCCS from Step 1 is unchanged.

Deliberate difference from Environ (inherited from #8075): for a charged slab, pcc_2d uses the monopole constant −πQL/(3A), whereas Environ uses −πQ/(3L).

Cavity derivatives: two paths. sccs_cav_deriv builds grad s and lapl s for the dielectric coefficient.
- Periodic cells keep Step 1's chain derivatives, as Environ deriv_method chain: grad s = s′ grad n and lapl s = s′ lapl n + s″ |grad n|², from FFT derivatives of the density n.
- With PCC the switching function s itself is differentiated on the FFT grid, as Environ deriv_method fft, because the chain coefficient is not converged at the cavity edge.
The PCC cases are therefore compared with QE in fft mode below. Periodic results are unchanged from Step 1. CavityPoint gains d2solute_drho2 for the chain path, which is checked against finite differences.

Validation against QE 7.6 + Environ 3.1.1

Case	ΔG ABACUS (eV)	ΔG QE (eV)	ΔΔG (meV)
H2O, PCC2D	−0.29933	−0.29932	−0.00
H3O⁺, PCC0D	−4.67264	−4.67271	+0.07
H3O⁺, PCC2D, 20 × 20 × 20 bohr (A = L²)	−2.07807	−2.07821	+0.14
H3O⁺, PCC2D, 12 × 20 × 12 bohr	−0.37602	−1.62666	+1250.6 (monopole constant, see above)

Cavity surface and volume agree to 0.01–0.02 bohr² and bohr³.
The electrostatic term E_sol_el + E_pcc agrees with QE's "electrostatic embedding" to ≤ 1.2 meV.
Solvation forces (solvent − vacuum) agree to 1.1e-4 eV/Å for neutral H2O with PCC2D. For H3O⁺ with PCC they differ by 3–5e-2 eV/Å; there QE's own analytic forces miss its finite differences by 4–6e-2 eV/Å. The lowpass filter in the next PR addresses force accuracy with PCC.

How the comparison was run. (reply to ABACUS-PR-BOT)

Each case directory has an ABACUS INPUT/STRU/KPT and a QE pw.in + environ.in.
One script runs them with OMP_NUM_THREADS=1:
- ABACUS: mpirun -np 8 abacus_std_para > run.log
- QE: mpirun -np 8 pw.x -environ -in pw.in > run.log
analyze.py takes ΔG from !FINAL_ETOT_IS (ABACUS) and ! total energy (QE). It reads the surface and volume from the SCCS_CAVITY line and from environ.debug, and the forces from TOTAL-FORCE and "Forces acting on atoms".
Executables:
- ABACUS: the stacked SCCS branch (v3.11.0-beta10), GCC 11, OpenMPI 5.0.10, FFTW 3.3.11, OpenBLAS 0.3.33, ELPA, LibXC 7.1.2.
- QE 7.6 + Environ 3.1.1.
The ABACUS energies were reproduced bit-for-bit. Since then the code has only been renamed and switched to the ModuleBase SI constants, which moves the solvation energies by about 2×10⁻⁸ eV.
Deferred checks: there are no charged integration cases (CI time; charged energies are validated in the table above). Force accuracy with PCC is addressed by the lowpass filter in the next PR.

ABACUS-PR-BOT

Static review of 0c2c11d. No builds or ABACUS runtime tests were run; CI diagnostics were unavailable.

Non-blocking: Please add the exact build/test/comparison commands, executable identity/configuration, MPI ranks and observed outcomes behind the validation table, noting which force/convergence checks remain deferred. Also state the generated INPUT-documentation workflow and whether documentation-generation/CLI checks were run.

Address ABACUS-PR-BOT review of SCCS step 2: no declaration in the header uses std::vector yet.

mohanchen · 2026-10-23T04:30:10Z

    const double net_charge = ionic_charge - electron_count;
-    if (config.cavity.epsilon_bulk <= 1.0 || std::abs(net_charge) <= 1e-6) { return std::string(); }
+    const bool periodic = config.boundary == ModuleSccs::Boundary::Periodic;
+    if (!periodic || config.cavity.epsilon_bulk <= 1.0 || std::abs(net_charge) <= 1e-6) { return std::string(); }


the 1e-6 seems to be a magic number

mohanchen · 2026-10-23T04:30:20Z

    }
-    if (std::abs(electron_error) > 1e-6)
+    // With PCC the PCC component reports the same mismatch.
+    if (config_.boundary == ModuleSccs::Boundary::Periodic && std::abs(electron_error) > 1e-6)


same here, the 1e-6 seems to be a magic number

mohanchen · 2026-10-23T04:32:00Z

+{
+    const bool orthogonal = unitcell::make_orthogonal_cell(cell.latvec, cell.lat0, 1e-10, geometry);
+    const bool cubic = orthogonal && make_pcc_0d_parameters(geometry, 1e-10, parameters);
+    if (!cubic) { ModuleBase::WARNING_QUIT("pcc_0d_geometry", "PCC 0D requires an equal-edge cubic cell"); }


Please do not write one-liner code here. To keep the structure as clear as possible, put each brace on its own line.

mohanchen · 2026-10-23T04:32:37Z

+        ModuleSccs::gauss_ion_rho(atoms, basis, tpiba,
+                                  ModuleSccs::gaussian_ion_spread, ions);
+        std::vector<double> solute_charge(basis.nrxx);
+        for (int ir = 0; ir < basis.nrxx; ++ir) { solute_charge[ir] = ions[ir] - density[ir]; }


Please do not write one-liner code here. To keep the structure as clear as possible, put each brace on its own line.

mohanchen · 2026-10-23T04:33:28Z

+        normal = cell.normal;
+        parameters = elecstate::make_pcc_2d_parameters(cell);
+        ModulePW::grid_positions(basis, lattice, length, positions);
+        for (auto& position : positions)


try to avoid using auto if possible

mohanchen · 2026-10-23T04:33:33Z

+    double integrate_product(const std::vector<double>& left, const std::vector<double>& right) const
+    {
+        double value = 0.0;
+        for (int ir = 0; ir < basis.nrxx; ++ir) { value += left[ir] * right[ir]; }


Please do not write one-liner code here. To keep the structure as clear as possible, put each brace on its own line.

mohanchen · 2026-10-23T04:33:59Z

+TEST_F(SccsPcc2dCoulombTest, ChargedPlanarModeMatchesAnalyticGauge)
+{
+    const double density_mean = 1e-3;
+    const double amplitude = 2e-4;


magic number, maybe adding some notes for this value?

Feature: SCCS with PCC 0D/2D open boundaries

0c2c11d

mohanchen requested a review from ABACUS-PR-BOT October 21, 2026 06:10

ABACUS-PR-BOT reviewed Oct 21, 2026

View reviewed changes

Comment thread source/source_io/module_parameter/read_inp_model.cpp

Comment thread source/source_hamilt/module_sccs/sccs_parameters.h Outdated

LKFEIYI and others added 2 commits October 21, 2026 17:28

Remove an unused include from sccs_parameters.h

03a486c

Address ABACUS-PR-BOT review of SCCS step 2: no declaration in the header uses std::vector yet.

Merge branch 'develop' into codex/sccs-pcc-1-coupling

57f0f66

mohanchen reviewed Oct 23, 2026

View reviewed changes

mohanchen added Feature Discussed The features will be discussed first but will not be implemented soon Refactor Refactor ABACUS codes Tests/Examples Issues/PR related to unit tests and integrate tests labels Oct 23, 2026

Navigation Menu

Repository navigation

Feature: periodic self-consistent continuum solvation (SCCS) Step2: SCCS with PCC 0D/2D - #8194

Feature: periodic self-consistent continuum solvation (SCCS) Step2: SCCS with PCC 0D/2D#8194
LKFEIYI wants to merge 3 commits into
deepmodeling:developfrom
LKFEIYI:codex/sccs-pcc-1-coupling

LKFEIYI commented Oct 21, 2026 •

edited

Loading

Uh oh!

ABACUS-PR-BOT left a comment

Uh oh!

Uh oh!

Uh oh!

mohanchen Oct 23, 2026

Uh oh!

mohanchen Oct 23, 2026

Uh oh!

mohanchen Oct 23, 2026

Uh oh!

mohanchen Oct 23, 2026

Uh oh!

mohanchen Oct 23, 2026

Uh oh!

mohanchen Oct 23, 2026

Uh oh!

mohanchen Oct 23, 2026

Uh oh!

This branch has not been deployed

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

LKFEIYI commented Oct 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Reminder

Linked Issue

What's changed?

Validation against QE 7.6 + Environ 3.1.1

Uh oh!

ABACUS-PR-BOT left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

mohanchen Oct 23, 2026

Choose a reason for hiding this comment

Uh oh!

mohanchen Oct 23, 2026

Choose a reason for hiding this comment

Uh oh!

mohanchen Oct 23, 2026

Choose a reason for hiding this comment

Uh oh!

mohanchen Oct 23, 2026

Choose a reason for hiding this comment

Uh oh!

mohanchen Oct 23, 2026

Choose a reason for hiding this comment

Uh oh!

mohanchen Oct 23, 2026

Choose a reason for hiding this comment

Uh oh!

mohanchen Oct 23, 2026

Choose a reason for hiding this comment

Uh oh!

This branch has not been deployed

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

LKFEIYI commented Oct 21, 2026 •

edited

Loading