fix(sdft): add CT (Chebyshev Trace) iter_header for pure SDFT without diagonalization (#7388)

* fix(sdft): add CT (Chebyshev Trace) iter_header for pure SDFT without diagonalization

Pure SDFT (nbands=0) does not perform KS diagonalization, yet the SCF
iteration table borrowed the ks_solver label (CG/DA/etc.). Add a "CT"
entry to iter_header_dict and use it when esolver_type=sdft with nbands=0.
Mixed SDFT (nbands>0) keeps the actual ks_solver label since it still
diagonalizes KS orbitals.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* test(sdft): add unit tests for SDFT iter_header CT label

Verify pure SDFT (nbands=0) outputs "CT" in ITER column, and mixed
SDFT (nbands>0) outputs the actual ks_solver label (e.g. "DA").

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: Cstandardlib

source/source_estate/elecstate_print.cpp

@@ -59,7 +59,8 @@ void print_scf_iterinfo(const std::string& ks_solver,
            {"cusolver", "CU"},
            {"bpcg", "BP"},
            {"pexsi", "PE"},
-           {"cusolvermp", "CM"}}; // I change the key of "cg_in_lcao" to "CG" because all the other are only two letters
+           {"cusolvermp", "CM"},
+           {"sdft", "CT"}}; // CT = Chebyshev Trace, for pure SDFT (nbands=0) where no H diagonalization is performed
     // ITER column
     std::vector<std::string> th_fmt = {" %-" + std::to_string(witer) + "s"}; // table header: th: ITER
     std::vector<std::string> td_fmt
@@ -374,7 +375,12 @@ void print_etot(const Magnetism& magnet,
         {
             drho.push_back(scf_thr_kin);
         }
-        elecstate::print_scf_iterinfo(PARAM.inp.ks_solver,
+        // Pure SDFT (nbands=0) uses Chebyshev trace (CT) since no H diagonalization is performed.
+        // Mixed SDFT (nbands>0) still diagonalizes KS orbitals, so use the actual ks_solver label.
+        const std::string iter_label = (PARAM.inp.esolver_type == "sdft" && PARAM.inp.nbands == 0)
+                                           ? "sdft"
+                                           : PARAM.inp.ks_solver;
+        elecstate::print_scf_iterinfo(iter_label,
                                       iter,
                                       6,
                                       mag,

source/source_estate/test/elecstate_print_test.cpp

@@ -258,3 +258,65 @@ TEST_F(ElecStatePrintTest, PrintEtotColorS4)
 
     delete elecstate.charge;
 }
+
+TEST_F(ElecStatePrintTest, PrintEtotSDFTPure)
+{
+    bool converged = false;
+    int iter = 1;
+    double scf_thr = 0.1;
+    double scf_thr_kin = 0.0;
+    double duration = 2.0;
+    double pw_diag_thr = 0.1;
+    int avg_iter = 2;
+    bool print = true;
+    elecstate.charge = new Charge;
+    elecstate.charge->nrxx = 100;
+    elecstate.charge->nxyz = 1000;
+
+    PARAM.input.out_freq_elec = 1;
+    PARAM.input.nspin = 1;
+    GlobalV::MY_RANK = 0;
+    // Pure SDFT: nbands=0, no KS diagonalization -> ITER column should show CT
+    PARAM.input.esolver_type = "sdft";
+    PARAM.input.nbands = 0;
+    PARAM.input.ks_solver = "cg";
+
+    testing::internal::CaptureStdout();
+    elecstate::print_etot(ucell.magnet, elecstate, converged, iter, scf_thr,
+                          scf_thr_kin, duration, pw_diag_thr, avg_iter, print);
+    output = testing::internal::GetCapturedStdout();
+    EXPECT_THAT(output, testing::HasSubstr("CT"));
+
+    delete elecstate.charge;
+}
+
+TEST_F(ElecStatePrintTest, PrintEtotSDFTMixed)
+{
+    bool converged = false;
+    int iter = 1;
+    double scf_thr = 0.1;
+    double scf_thr_kin = 0.0;
+    double duration = 2.0;
+    double pw_diag_thr = 0.1;
+    int avg_iter = 2;
+    bool print = true;
+    elecstate.charge = new Charge;
+    elecstate.charge->nrxx = 100;
+    elecstate.charge->nxyz = 1000;
+
+    PARAM.input.out_freq_elec = 1;
+    PARAM.input.nspin = 1;
+    GlobalV::MY_RANK = 0;
+    // Mixed SDFT: nbands>0, still diagonalizes KS orbitals -> ITER column shows ks_solver label
+    PARAM.input.esolver_type = "sdft";
+    PARAM.input.nbands = 5;
+    PARAM.input.ks_solver = "dav";
+
+    testing::internal::CaptureStdout();
+    elecstate::print_etot(ucell.magnet, elecstate, converged, iter, scf_thr,
+                          scf_thr_kin, duration, pw_diag_thr, avg_iter, print);
+    output = testing::internal::GetCapturedStdout();
+    EXPECT_THAT(output, testing::HasSubstr("DA"));
+
+    delete elecstate.charge;
+}