diff --git a/source/module_hsolver/diago_david.cpp b/source/module_hsolver/diago_david.cpp
index 20f87f2c76..e74e7f787d 100644
--- a/source/module_hsolver/diago_david.cpp
+++ b/source/module_hsolver/diago_david.cpp
@@ -110,6 +110,14 @@ DiagoDavid<T, Device>::DiagoDavid(const Real* precondition_in,
     // lagrange_matrix(nband, nband); // for orthogonalization
     resmem_complex_op()(this->ctx, this->lagrange_matrix, nband * nband);
     setmem_complex_op()(this->ctx, this->lagrange_matrix, 0, nband * nband);
+
+#if defined(__CUDA) || defined(__ROCM)
+    if (this->device == base_device::GpuDevice)
+    {
+        resmem_var_op()(this->ctx, this->d_precondition, dim);
+        syncmem_var_h2d_op()(this->ctx, this->cpu_ctx, this->d_precondition, this->precondition, dim);
+    }
+#endif
 }
 
 /**
@@ -130,6 +138,13 @@ DiagoDavid<T, Device>::~DiagoDavid()
     delmem_complex_op()(this->ctx, this->vcc);
     delmem_complex_op()(this->ctx, this->lagrange_matrix);
     base_device::memory::delete_memory_op<Real, base_device::DEVICE_CPU>()(this->cpu_ctx, this->eigenvalue);
+    // If the device is a GPU device, free the d_precondition array.
+#if defined(__CUDA) || defined(__ROCM)
+    if (this->device == base_device::GpuDevice)
+    {
+        delmem_var_op()(this->ctx, this->d_precondition);
+    }
+#endif
 }
 
 template <typename T, typename Device>
@@ -1135,14 +1150,6 @@ int DiagoDavid<T, Device>::diag(const HPsiFunc& hpsi_func,
     int ntry = 0;
     this->notconv = 0;
 
-#if defined(__CUDA) || defined(__ROCM)
-    if (this->device == base_device::GpuDevice)
-    {
-        resmem_var_op()(this->ctx, this->d_precondition, ldPsi);
-        syncmem_var_h2d_op()(this->ctx, this->cpu_ctx, this->d_precondition, this->precondition, ldPsi);
-    }
-#endif
-
     int sum_dav_iter = 0;
     do
     {
@@ -1155,14 +1162,6 @@ int DiagoDavid<T, Device>::diag(const HPsiFunc& hpsi_func,
         std::cout << "\n notconv = " << this->notconv;
         std::cout << "\n DiagoDavid::diag', too many bands are not converged! \n";
     }
-    // If the device is a GPU device, free the d_precondition array.
-#if defined(__CUDA) || defined(__ROCM)
-    if (this->device == base_device::GpuDevice)
-    {
-        delmem_var_op()(this->ctx, this->d_precondition);
-    }
-#endif
-
     return sum_dav_iter;
 }