Remove DiagH of lcao PEXSI (#5259)

* Remove Base DiagH class of DiagoLapack

* Remove DiagH Base class of DiagoScalapack and lcao test

* Remove DiagH Base class of DiagoCusolver and lcao_cusolver_test

* Update docs in hsolver

* Remove Base DiagH pointer in diago_lapack_test

* Remove Base DiagH of DiagoElpa

* Remove Base DiagH of DiagoElpaNative

* Remove Base DiagH of DiagoCusolverMP

* Remove Base DiagH of DiagoPexsi

---------

Co-authored-by: Haozhi Han <[email protected]>

Author: Cstandardlib

source/module_hsolver/diago_cusolvermp.h

@@ -8,7 +8,7 @@
 #include "module_hsolver/kernels/cuda/diag_cusolvermp.cuh"
 namespace hsolver
 {
-// DiagoCusolverMP class, derived from DiagH, for diagonalization using CUSOLVERMP
+// DiagoCusolverMP class, for diagonalization using CUSOLVERMP
 template <typename T>
 class DiagoCusolverMP
 {

source/module_hsolver/diago_pexsi.h

@@ -12,15 +12,15 @@ namespace hsolver
 {
 
 template <typename T>
-class DiagoPexsi : public DiagH<T>
+class DiagoPexsi
 {
   private:
     using Real = typename GetTypeReal<T>::type;
     static std::vector<double> mu_buffer;
 
   public:
     DiagoPexsi(const Parallel_Orbitals* ParaV_in);
-    void diag(hamilt::Hamilt<T>* phm_in, psi::Psi<T>& psi, Real* eigenvalue_in) override;
+    void diag(hamilt::Hamilt<T>* phm_in, psi::Psi<T>& psi, Real* eigenvalue_in);
     const Parallel_Orbitals* ParaV;
     std::vector<T*> DM;
     std::vector<T*> EDM;