Refactor XC_Functional_Libxc::convert_vtxc_v() (#5212)

* Fix memory bug in XC_Functional_Libxc::cal_gdr()

* Refactor XC_Functional_Libxc::convert_vtxc_v()

Author: PeizeLin

source/module_hamilt_general/module_xc/xc_functional_libxc.h

@@ -96,7 +96,7 @@ namespace XC_Functional_Libxc
 		std::vector<double> exc);
 
 	// converting vtxc and v from vrho and vsigma (libxc=>abacus)
-	extern double convert_vtxc_v(
+	extern std::pair<double,ModuleBase::matrix> convert_vtxc_v(
 		const xc_func_type &func,
 		const int nspin,
 		const std::size_t nrxx,
@@ -106,8 +106,7 @@ namespace XC_Functional_Libxc
 		const std::vector<double> &vrho,
 		const std::vector<double> &vsigma,
 		const double tpiba,
-		const Charge* const chr,
-		ModuleBase::matrix &v);
+		const Charge* const chr);
 
 	// dh for gga v
 	extern std::vector<std::vector<double>> cal_dh(

source/module_hamilt_general/module_xc/xc_functional_libxc_tools.cpp

@@ -163,8 +163,8 @@ double XC_Functional_Libxc::convert_etxc(
 	return etxc;
 }
 
-// converting etxc from exc (libxc=>abacus)
-double XC_Functional_Libxc::convert_vtxc_v(
+// converting vtxc and v from vrho and vsigma (libxc=>abacus)
+std::pair<double,ModuleBase::matrix> XC_Functional_Libxc::convert_vtxc_v(
 	const xc_func_type &func,
 	const int nspin,
 	const std::size_t nrxx,
@@ -174,13 +174,10 @@ double XC_Functional_Libxc::convert_vtxc_v(
 	const std::vector<double> &vrho,
 	const std::vector<double> &vsigma,
 	const double tpiba,
-	const Charge* const chr,
-	ModuleBase::matrix &v)
+	const Charge* const chr)
 {
-	assert(v.nr==nspin);
-	assert(v.nc==nrxx);
-
 	double vtxc = 0.0;
+	ModuleBase::matrix v(nspin, nrxx);
 
 	#ifdef _OPENMP
 	#pragma omp parallel for collapse(2) reduction(+:vtxc) schedule(static, 256)
@@ -215,7 +212,7 @@ double XC_Functional_Libxc::convert_vtxc_v(
 		vtxc -= rvtxc;
 	} // end if(func.info->family == XC_FAMILY_GGA || func.info->family == XC_FAMILY_HYB_GGA))
 
-	return vtxc;
+	return std::make_pair(vtxc, std::move(v));
 }
 
 

source/module_hamilt_general/module_xc/xc_functional_libxc_vxc.cpp

@@ -110,12 +110,13 @@ std::tuple<double,double,ModuleBase::matrix> XC_Functional_Libxc::v_xc_libxc(		/
         }
 
         etxc += XC_Functional_Libxc::convert_etxc(nspin, nrxx, sgn, rho, exc);
-        vtxc += XC_Functional_Libxc::convert_vtxc_v(
+        const std::pair<double,ModuleBase::matrix> vtxc_v = XC_Functional_Libxc::convert_vtxc_v(
             func, nspin, nrxx,
             sgn, rho, gdr,
             vrho, vsigma,
-            tpiba, chr,
-            v);
+            tpiba, chr);
+        vtxc += std::get<0>(vtxc_v);
+        v += std::get<1>(vtxc_v);
     } // end for( xc_func_type &func : funcs )
 
     if(4==PARAM.inp.nspin)