[lanshuyue]

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

No linked issue: this is a behavior-preserving maintainability refactor prompted by the code-quality report for dftu_nao_op.cpp.

Unit Tests and/or Case Tests for my changes

• Commands run:
  • cmake --build build --target MODULE_DFTU_op abacus_basic_para -j2
  • OMP_NUM_THREADS=1 ctest --test-dir build --output-on-failure -R '^MODULE_DFTU_op$'
  • OMP_NUM_THREADS=1 ../integrate/Autotest.sh -a <new-binary> -f /tmp/dftu_refactor_cases.txt -n 4 -o 1 -j 1
  • The same integration command with the saved pre-refactor binary for an A/B comparison.
  • python3 tools/03_code_analysis/code_quality_score.py --format json source/source_lcao/module_dftu/dftu_nao_op.cpp
  • python3 tools/03_code_analysis/agent_governance_check.py --staged
  • git diff --check
• Result summary:
  • Focused unit-test target and the main abacus_basic_para executable compiled successfully.
  • MODULE_DFTU_op passed (1/1).
  • The refactored and saved pre-refactor executables produced identical energies for both symmetry=1, kpar=4 A/B cases:
    • 03_LCAO_DFTU_S2_Z: -6771.69033022 eV with both binaries.
    • 04_LCAO_DFTU_S4_XY: -6763.40685034 eV with both binaries.
  • The integration harness still reports the same pre-existing reference deviations for both binaries. Case 04 is already disabled in CASES_CPU.txt for convergence/numerical-stability reasons. The A/B comparison confirms this refactor introduces no numerical change.
  • Code-quality score improved from 82 to 96. The only remaining deduction is the existing 11-parameter constructor, intentionally left unchanged to avoid an interface-level refactor.
  • Governance and whitespace checks completed without blocking findings.
• Checks not run, with reason:
  • pre-commit was unavailable in the local environment (pre-commit: command not found). Equivalent staged governance and whitespace checks were run directly.

What's changed?

• Split DFTU_onsite::contributeHR() into focused helpers for symmetry decisions, rotation setup, full-BZ k-vector construction, Hubbard-atom accumulation, and spin post-processing.
• Keep the temporary symmetry-restored density matrix on the stack and consume it within its owning helper, removing the raw new allocation.
• Wrap lines longer than 120 characters.
• Preserve the constructor and all external interfaces.

Governance Notes

• INPUT/docs changes: none; this refactor does not change user-visible behavior or INPUT parameters.
• Core module impact: limited to the LCAO DFT+U onsite operator implementation. Hamiltonian assembly order, occupation handling, symmetry restoration, spin handling, and numerical results are unchanged.
• Exceptions requested: none.

[lanshuyue]

@ABACUS-PR-BOT

[ABACUS-PR-BOT]

Static review of eb03771c, including an independent pass, found no new correctness defects in this extraction. One non-blocking memory-lifetime suggestion is inline. Static governance and whitespace checks passed; builds, numerical/MPI tests, and CI were not independently verified.