deepmodeling · mohanchen · Jan 15, 2026 · Jan 14, 2026
diff --git a/source/source_cell/klist.cpp b/source/source_cell/klist.cpp
@@ -566,7 +566,19 @@ void K_Vectors::normalize_wk(const int& degspin)
     {
         sum += this->wk[ik];
     }
-    assert(sum > 0.0);
+
+    // If sum of weights is zero or very small, set equal weights
+    if (sum < 1e-10)
+    {
+        ModuleBase::WARNING("K_Vectors::normalize_wk",
+                            "Sum of k-point weights is zero or very small. "
+                            "Setting equal weights for all k-points.");
+        for (int ik = 0; ik < nkstot; ik++)
+        {
+            this->wk[ik] = 1.0 / double(nkstot);
+        }
+        sum = 1.0;
+    }
 
     for (int ik = 0; ik < nkstot; ik++)
     {

diff --git a/source/source_cell/klist.h b/source/source_cell/klist.h
@@ -273,7 +273,8 @@ class K_Vectors
      * @return void
      *
      * @note This function should only be called by the master process (MY_RANK == 0).
-     * @note The function assumes that the sum of the weights of the k-points is greater than 0.
+     * @note If the sum of the weights is zero or very small (< 1e-10), the function will set equal weights for all
+     * k-points and issue a warning. This allows calculations like get_wf to proceed with zero-weight k-points.
      * @note The function first normalizes the weights so that their sum is 1, and then scales them by the degeneracy of
      * spin.
      */

diff --git a/source/source_cell/test/klist_test.cpp b/source/source_cell/test/klist_test.cpp
@@ -727,6 +727,32 @@ TEST_F(KlistTest, NormalizeWk)
     EXPECT_DOUBLE_EQ(kv->wk[1], 1.0);
 }
 
+TEST_F(KlistTest, NormalizeWkZeroWeights)
+{
+    // Test that zero weights are handled correctly
+    kv->nspin = 1;
+    kv->set_nkstot(3);
+    kv->set_nks(3);
+    kv->renew(kv->get_nkstot());
+    kv->wk[0] = 0.0;
+    kv->wk[1] = 0.0;
+    kv->wk[2] = 0.0;
+    int deg = 2;
+
+    // Should not crash and should set equal weights
+    kv->normalize_wk(deg);
+
+    // Each k-point should have weight = deg / nkstot = 2 / 3
+    EXPECT_NEAR(kv->wk[0], 2.0 / 3.0, 1e-10);
+    EXPECT_NEAR(kv->wk[1], 2.0 / 3.0, 1e-10);
+    EXPECT_NEAR(kv->wk[2], 2.0 / 3.0, 1e-10);
+
+    // Sum should equal deg
+    double sum = kv->wk[0] + kv->wk[1] + kv->wk[2];
+    EXPECT_NEAR(sum, 2.0, 1e-10);
+}
+
+
 TEST_F(KlistTest, UpdateUseIBZ)
 {
     kv->nspin = 1;

diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/INPUT b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/INPUT
@@ -0,0 +1,24 @@
+INPUT_PARAMETERS
+suffix          autotest
+
+#calculation     scf
+#out_wfc_lcao    1 
+
+calculation     get_wf
+symmetry        -1
+nbands			2
+nspin           2
+pseudo_dir	    ../../PP_ORB
+orbital_dir	    ../../PP_ORB
+latname			sc
+ecutwfc			25.0
+basis_type		lcao 	
+scf_thr			1e-10
+read_file_dir	./
+
+out_wfc_norm    1
+out_wfc_re_im   1
+
+bx 2
+by 2
+bz 2
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/KPT b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/KPT
@@ -0,0 +1,6 @@
+K_POINTS
+3
+Direct
+0.0000  0.0000  0.0000  0.0
+0.3333  0.0000  0.0000  0.0
+0.6667  0.0000  0.0000  0.0
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/README b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/README
@@ -0,0 +1,3 @@
+Test the 'calculation get_wf' option with zero-weight k-points.
+This test verifies that ABACUS can handle k-points with zero weights
+by automatically assigning equal weights and issuing a warning.
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/STRU b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/STRU
@@ -0,0 +1,19 @@
+#This is the atom file containing all the information
+#about the lattice structure.
+
+ATOMIC_SPECIES
+H 1.0008  H_ONCV_PBE-1.0.upf 
+
+NUMERICAL_ORBITAL
+H_gga_6au_60Ry_2s1p.orb
+
+LATTICE_CONSTANT
+10.0  			#Lattice constant
+
+ATOMIC_POSITIONS
+Cartesian   		#Cartesian(Unit is LATTICE_CONSTANT)
+H 			#Name of element	
+0.0			#Magnetic for this element.
+2			#Number of atoms
+0.00 0.00 -0.0661400 0 0 0	#x,y,z, move_x, move_y, move_z
+0.00 0.00  0.0661400 0 0 0	#x,y,z, move_x, move_y, move_z
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/result.ref b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/result.ref
@@ -0,0 +1,19 @@
+wfi1s1k1.cube -11.77152988
+wfi1s1k1im.cube 0
+wfi1s1k1re.cube -11.77169544
+wfi1s1k2.cube -3.754629032
+wfi1s1k2im.cube -5.256421773e-15
+wfi1s1k2re.cube -3.754662163
+wfi1s1k3.cube -3.754629032
+wfi1s1k3im.cube -2.592407863e-14
+wfi1s1k3re.cube -3.754662163
+wfi1s2k1.cube -11.77152988
+wfi1s2k1im.cube 0
+wfi1s2k1re.cube -15.5263576
+wfi1s2k2.cube -3.754629032
+wfi1s2k2im.cube 8.143533574e-14
+wfi1s2k2re.cube -7.509324327
+wfi1s2k3.cube -3.754629032
+wfi1s2k3im.cube -3.563679367e-14
+wfi1s2k3re.cube -7.509324327
+totaltimeref 0.22
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk1s1_nao.txt b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk1s1_nao.txt
@@ -0,0 +1,14 @@
+1 (index of k points)
+0 0 0
+2 (number of bands)
+10 (number of orbitals)
+1 (band)
+-7.51324209e-01 (Ry)
+3.33333333e-01 (Occupations)
+-5.37247451e-01 0.00000000e+00 -3.61675036e-02 0.00000000e+00 -1.54180993e-02 0.00000000e+00 -6.00760481e-17 0.00000000e+00 4.95327447e-17 0.00000000e+00 
+-5.37247451e-01 0.00000000e+00 -3.61675036e-02 0.00000000e+00 1.54180993e-02 0.00000000e+00 7.40355316e-17 0.00000000e+00 -2.60742120e-17 0.00000000e+00 
+2 (band)
+4.36966415e-01 (Ry)
+0.00000000e+00 (Occupations)
+-1.75242688e+00 0.00000000e+00 4.89257747e-01 0.00000000e+00 -1.47270024e-02 0.00000000e+00 2.73797359e-16 0.00000000e+00 5.21506844e-17 0.00000000e+00 
+1.75242688e+00 0.00000000e+00 -4.89257747e-01 0.00000000e+00 -1.47270024e-02 0.00000000e+00 -1.13418218e-16 0.00000000e+00 -1.40732906e-16 0.00000000e+00 
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk1s2_nao.txt b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk1s2_nao.txt
@@ -0,0 +1,14 @@
+4 (index of k points)
+0 0 0
+2 (number of bands)
+10 (number of orbitals)
+1 (band)
+-7.51324209e-01 (Ry)
+3.33333333e-01 (Occupations)
+-5.37247451e-01 0.00000000e+00 -3.61675036e-02 0.00000000e+00 -1.54180993e-02 0.00000000e+00 2.25946347e-17 0.00000000e+00 -3.23946428e-17 0.00000000e+00 
+-5.37247451e-01 0.00000000e+00 -3.61675036e-02 0.00000000e+00 1.54180993e-02 0.00000000e+00 -4.69322153e-17 0.00000000e+00 9.89372825e-18 0.00000000e+00 
+2 (band)
+4.36966415e-01 (Ry)
+0.00000000e+00 (Occupations)
+-1.75242688e+00 0.00000000e+00 4.89257747e-01 0.00000000e+00 -1.47270024e-02 0.00000000e+00 -2.23164913e-16 0.00000000e+00 -1.71182391e-16 0.00000000e+00 
+1.75242688e+00 0.00000000e+00 -4.89257747e-01 0.00000000e+00 -1.47270024e-02 0.00000000e+00 -2.19012650e-16 0.00000000e+00 1.56688230e-16 0.00000000e+00 
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk2s1_nao.txt b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk2s1_nao.txt
@@ -0,0 +1,14 @@
+2 (index of k points)
+0.33333333 0 0
+2 (number of bands)
+10 (number of orbitals)
+1 (band)
+-7.50769326e-01 (Ry)
+3.33333333e-01 (Occupations)
+-5.37427336e-01 -1.05559980e-18 -3.71097795e-02 5.89767804e-19 -1.53531997e-02 -2.52000064e-19 -6.10794919e-17 -2.98003376e-04 4.28540990e-17 -6.70070819e-20 
+-5.37427336e-01 1.15844342e-18 -3.71097795e-02 -5.70793079e-19 1.53531997e-02 -1.99414845e-19 7.22531527e-17 -2.98003376e-04 -2.77072393e-17 7.08987808e-20 
+2 (band)
+4.40705472e-01 (Ry)
+0.00000000e+00 (Occupations)
+-1.74611098e+00 1.79777627e-18 4.85703522e-01 2.96309663e-18 -9.76081786e-03 1.02686625e-19 2.79195633e-16 -7.11522605e-04 1.78966954e-16 -2.29212014e-18 
+1.74611098e+00 -1.30843780e-18 -4.85703522e-01 3.69605802e-18 -9.76081786e-03 -1.72277732e-18 -1.27636301e-16 7.11522605e-04 -9.62680330e-17 1.00089304e-19 
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk2s2_nao.txt b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk2s2_nao.txt
@@ -0,0 +1,14 @@
+5 (index of k points)
+0.33333333 0 0
+2 (number of bands)
+10 (number of orbitals)
+1 (band)
+-7.50769326e-01 (Ry)
+3.33333333e-01 (Occupations)
+-5.37427336e-01 -1.06901834e-18 -3.71097795e-02 9.88948368e-19 -1.53531997e-02 1.80111026e-20 1.14141119e-17 -2.98003376e-04 -3.06324474e-17 -1.14953806e-19 
+-5.37427336e-01 1.17059117e-18 -3.71097795e-02 -6.82945997e-19 1.53531997e-02 1.67973109e-19 -5.00148318e-17 -2.98003376e-04 9.69124493e-18 4.66316044e-20 
+2 (band)
+4.40705472e-01 (Ry)
+0.00000000e+00 (Occupations)
+-1.74611098e+00 -2.08369602e-18 4.85703522e-01 -1.37343732e-17 -9.76081786e-03 1.67507422e-18 -3.24174080e-17 -7.11522605e-04 -2.44161562e-16 -1.32000126e-18 
+1.74611098e+00 -7.08124980e-19 -4.85703522e-01 -1.23075988e-17 -9.76081786e-03 2.63869504e-18 -1.40848625e-16 7.11522605e-04 1.21290669e-16 1.14340373e-18 
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk3s1_nao.txt b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk3s1_nao.txt
@@ -0,0 +1,14 @@
+3 (index of k points)
+0.66666667 0 0
+2 (number of bands)
+10 (number of orbitals)
+1 (band)
+-7.50769326e-01 (Ry)
+3.33333333e-01 (Occupations)
+-5.37427336e-01 1.25616529e-18 -3.71097795e-02 -5.11002849e-19 -1.53531997e-02 2.62263916e-19 -7.47922807e-17 2.98003376e-04 4.23522015e-17 1.46891825e-19 
+-5.37427336e-01 -1.25520762e-18 -3.71097795e-02 6.78972343e-19 1.53531997e-02 3.53226637e-19 7.22078030e-17 2.98003376e-04 -2.67636433e-17 -1.69280472e-19 
+2 (band)
+4.40705472e-01 (Ry)
+0.00000000e+00 (Occupations)
+-1.74611098e+00 -4.13533757e-18 4.85703522e-01 -4.94201126e-18 -9.76081786e-03 1.06240055e-18 2.77206952e-16 7.11522605e-04 1.61957571e-16 2.65671499e-18 
+1.74611098e+00 2.68898237e-18 -4.85703522e-01 -7.21715533e-18 -9.76081786e-03 5.06512961e-19 -1.24025501e-16 -7.11522605e-04 -9.08141901e-17 4.33505600e-20 
diff --git a/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk3s2_nao.txt b/tests/03_NAO_multik/32_NO_KP_get_wf_zero_weight/wfk3s2_nao.txt
@@ -0,0 +1,14 @@
+6 (index of k points)
+0.66666667 0 0
+2 (number of bands)
+10 (number of orbitals)
+1 (band)
+-7.50769326e-01 (Ry)
+3.33333333e-01 (Occupations)
+-5.37427336e-01 8.61417023e-19 -3.71097795e-02 -6.23082852e-19 -1.53531997e-02 2.44581316e-21 1.16838265e-17 2.98003376e-04 -2.92860654e-17 8.50798608e-20 
+-5.37427336e-01 -9.02644351e-19 -3.71097795e-02 5.33082486e-19 1.53531997e-02 -1.02404229e-19 -5.05065573e-17 2.98003376e-04 1.04755659e-17 -9.40792559e-20 
+2 (band)
+4.40705472e-01 (Ry)
+0.00000000e+00 (Occupations)
+-1.74611098e+00 2.39469645e-18 4.85703522e-01 1.09268415e-17 -9.76081786e-03 -1.48128168e-18 -3.40426592e-17 7.11522605e-04 -2.47663622e-16 3.17776521e-18 
+1.74611098e+00 3.42509704e-19 -4.85703522e-01 1.00219566e-17 -9.76081786e-03 -9.76641093e-19 -1.37890471e-16 -7.11522605e-04 1.27874741e-16 -1.32051002e-18 
diff --git a/tests/03_NAO_multik/CASES_CPU.txt b/tests/03_NAO_multik/CASES_CPU.txt
@@ -30,6 +30,7 @@
 30_NO_KP_S2_eminus
 31_NO_KP_nupdown0
 32_NO_KP_get_wf
+32_NO_KP_get_wf_zero_weight
 33_NO_KP_OW
 34_NO_KP_MU
 35_NO_KP_MU_nscf