Feature: support the default as the value of dft_functional when initialize vdw

source/module_hamilt_general/module_vdw/test/vdw_test.cpp

@@ -377,7 +377,7 @@ class vdwd3Test: public testing::Test
 TEST_F(vdwd3Test, D30Default)
 {
     vdw::Vdwd3 vdwd3_test(ucell);
-    vdwd3_test.parameter().initial_parameters(input);
+    vdwd3_test.parameter().initial_parameters("pbe", input);
 
     EXPECT_EQ(vdwd3_test.parameter().s6(), 1.0);
     EXPECT_EQ(vdwd3_test.parameter().s18(), 0.7875);
@@ -396,7 +396,8 @@ TEST_F(vdwd3Test, D30UnitA)
     input.vdw_cn_thr_unit = "A";
     vdw::Vdwd3 vdwd3_test(ucell);
 
-    vdwd3_test.parameter().initial_parameters(input);
+    const std::string xc = "pbe";
+    vdwd3_test.parameter().initial_parameters(xc, input);
 
     EXPECT_EQ(vdwd3_test.parameter().rthr2(), std::pow(95/ModuleBase::BOHR_TO_A, 2));
     EXPECT_EQ(vdwd3_test.parameter().cn_thr2(), std::pow(40/ModuleBase::BOHR_TO_A, 2));   
@@ -407,7 +408,8 @@ TEST_F(vdwd3Test, D30Period)
     input.vdw_cutoff_type = "period";
     vdw::Vdwd3 vdwd3_test(ucell);
 
-    vdwd3_test.parameter().initial_parameters(input);
+    const std::string xc = "pbe";
+    vdwd3_test.parameter().initial_parameters(xc, input);
     vdwd3_test.init();
     std::vector<int> rep_vdw_ref = {input.vdw_cutoff_period.x, input.vdw_cutoff_period.y, input.vdw_cutoff_period.z};
 

source/module_hamilt_general/module_vdw/vdw.cpp

@@ -1,7 +1,41 @@
+#include <algorithm>
+#include <cassert>
 
 #include "vdw.h"
 #include "vdwd2.h"
 #include "vdwd3.h"
+#include "module_base/tool_quit.h"
+
+std::string parse_xcname(const std::string &xc_input,
+                         const std::vector<std::string> &xc_psp)
+{
+    if (xc_input != "default")
+    {
+        return xc_input;
+    }
+
+    if (xc_psp.size() <= 0)
+    {
+        ModuleBase::WARNING_QUIT("ModuleHamiltGeneral::ModuleVDW::parse_xcname", 
+        "XC name automatic inference failed: no pseudopotential files are found");
+    }
+    std::vector<std::string> xc_psp_uniq = xc_psp;
+    std::sort(xc_psp_uniq.begin(), xc_psp_uniq.end());
+    auto last = std::unique(xc_psp_uniq.begin(), xc_psp_uniq.end());
+    xc_psp_uniq.erase(last, xc_psp_uniq.end());
+
+    if (xc_psp_uniq.size() > 1)
+    {
+        ModuleBase::WARNING_QUIT("ModuleHamiltGeneral::ModuleVDW::parse_xcname", 
+        "XC name automatic inference failed: inconsistency in XC names is found"
+        " in the pseudopotential files");
+    }
+    const std::string xc = xc_psp_uniq[0];
+    std::cout << "ModuleHamiltGeneral::ModuleVDW::parse_xcname: "
+              << "XC name is automatically inferred from pseudopotential as `" 
+              << xc << "`" << std::endl;
+    return xc;
+}
 
 namespace vdw
 {
@@ -24,8 +58,13 @@ std::unique_ptr<Vdw> make_vdw(const UnitCell &ucell,
     }
     else if (input.vdw_method == "d3_0" || input.vdw_method == "d3_bj")
     {
+        std::vector<std::string> xc_psp(ucell.ntype);
+        for (int it = 0; it < ucell.ntype; it++)
+        {
+            xc_psp[it] = ucell.atoms[it].ncpp.xc_func;
+        }
         std::unique_ptr<Vdwd3> vdw_ptr = make_unique<Vdwd3>(ucell);
-        vdw_ptr->parameter().initial_parameters(input, plog);
+        vdw_ptr->parameter().initial_parameters(parse_xcname(input.dft_functional, xc_psp), input, plog);
         return vdw_ptr;
     }
     else if (input.vdw_method != "none")

source/module_hamilt_general/module_vdw/vdw.h

@@ -11,9 +11,10 @@
 namespace vdw
 {
 
-template<typename T, typename... Args>
-std::unique_ptr<T> make_unique(Args &&... args) {
-    return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+    template<typename T, typename... Args>
+    std::unique_ptr<T> make_unique(Args &&... args) {
+        return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+
 }
 
 class Vdw

source/module_hamilt_general/module_vdw/vdwd3_parameters.cpp

@@ -10,7 +10,9 @@
 namespace vdw
 {
 
-void Vdwd3Parameters::initial_parameters(const Input_para &input, std::ofstream* plog)
+void Vdwd3Parameters::initial_parameters(const std::string& xc,
+                                         const Input_para& input, 
+                                         std::ofstream* plog)
 {
     // initialize the dftd3 parameters
     mxc_.resize(max_elem_, 1);
@@ -23,7 +25,7 @@ void Vdwd3Parameters::initial_parameters(const Input_para &input, std::ofstream*
                          5,
                          std::vector<std::vector<double>>(max_elem_, std::vector<double>(max_elem_, 0.0)))));
 
-    _vdwd3_autoset_xcparam(input.dft_functional, input.vdw_method,
+    _vdwd3_autoset_xcparam(xc, input.vdw_method,
                            input.vdw_s6, input.vdw_s8, input.vdw_a1, input.vdw_a2,
                            s6_, s18_, rs6_, rs18_, /* rs6: a1, rs18: a2 */
                            plog);

source/module_hamilt_general/module_vdw/vdwd3_parameters.h

@@ -27,7 +27,8 @@ class Vdwd3Parameters : public VdwParameters
      * @param input Parameter instance
      * @param plog optional, for logging the parameter setting process
      */
-    void initial_parameters(const Input_para &input, 
+    void initial_parameters(const std::string& xc,
+                            const Input_para& input, 
                             std::ofstream* plog = nullptr); // for logging the parameter autoset
 
     inline const std::string &version() const { return version_; }