Feature: add nbands_mul for setting multiply for default nbands and fix initial mag for SOC

docs/advanced/input_files/input-main.md

@@ -60,6 +60,7 @@
     - [basis\_type](#basis_type)
     - [ks\_solver](#ks_solver)
     - [nbands](#nbands)
+    - [nbands_mul](#nbands_mul)
     - [nelec](#nelec)
     - [nelec\_delta](#nelec_delta)
     - [nupdown](#nupdown)
@@ -967,9 +968,15 @@ calculations.
 - **Type**: Integer
 - **Description**: The number of Kohn-Sham orbitals to calculate. It is recommended to setup this value, especially when smearing techniques are utilized, more bands should be included.
 - **Default**:
-  - nspin=1: max(1.2\*occupied_bands, occupied_bands + 10)
-  - nspin=2: max(1.2\*nelec_spin, nelec_spin + 10), in which nelec_spin = max(nelec_spin_up, nelec_spin_down)
-  - nspin=4: max(1.2\*nelec, nelec + 20)
+  - nspin=1: max(`nbands_mul`\*occupied_bands, occupied_bands + 10)
+  - nspin=2: max(`nbands_mul`\*nelec_spin, nelec_spin + 10), in which nelec_spin = max(nelec_spin_up, nelec_spin_down)
+  - nspin=4: max(`nbands_mul`\*nelec, nelec + 20)
+
+### nbands_mul
+
+- **Type**: Real
+- **Description**: the multiply value of default formular of `nbands`. It is recommended that the user set a larger default multiplier for systems with complex electron levels near the Fermi surface, such as `2.0`.
+- **Default**: 1.2
 
 ### nelec
 

source/module_cell/read_atoms.cpp

@@ -862,7 +862,9 @@ bool UnitCell::read_atom_positions(std::ifstream &ifpos, std::ofstream &ofs_runn
                 }
             }
         }
-        if (autoset_mag)
+	// atomic initial magnetism will be autoset if user set zero for every atom
+	// one exception is `lspinorb 1` with `noncolin 0`, this setting imply no-mag material but SOC included
+        if (autoset_mag && !PARAM.inp.lspinorb || PARAM.inp.noncolin)
         {
             if(PARAM.inp.nspin==4)
             {

source/module_elecstate/cal_nelec_nband.cpp

@@ -84,7 +84,7 @@ void cal_nbands(const int& nelec, const int& nlocal, const std::vector<double>&
         if (PARAM.inp.nspin == 1)
         {
             const int nbands1 = static_cast<int>(occupied_bands) + 10;
-            const int nbands2 = static_cast<int>(1.2 * occupied_bands) + 1;
+            const int nbands2 = static_cast<int>(PARAM.inp.nbands_mul * occupied_bands) + 1;
             nbands = std::max(nbands1, nbands2);
             if (PARAM.inp.basis_type != "pw") {
                 nbands = std::min(nbands, nlocal);
@@ -93,7 +93,7 @@ void cal_nbands(const int& nelec, const int& nlocal, const std::vector<double>&
         else if (PARAM.inp.nspin == 4)
         {
             const int nbands3 = nelec + 20;
-            const int nbands4 = static_cast<int>(1.2 * nelec) + 1;
+            const int nbands4 = static_cast<int>(PARAM.inp.nbands_mul * nelec) + 1;
             nbands = std::max(nbands3, nbands4);
             if (PARAM.inp.basis_type != "pw") {
                 nbands = std::min(nbands, nlocal);
@@ -103,7 +103,7 @@ void cal_nbands(const int& nelec, const int& nlocal, const std::vector<double>&
         {
             const double max_occ = std::max(nelec_spin[0], nelec_spin[1]);
             const int nbands3 = static_cast<int>(max_occ) + 11;
-            const int nbands4 = static_cast<int>(1.2 * max_occ) + 1;
+            const int nbands4 = static_cast<int>(PARAM.inp.nbands_mul * max_occ) + 1;
             nbands = std::max(nbands3, nbands4);
             if (PARAM.inp.basis_type != "pw") {
                 nbands = std::min(nbands, nlocal);

source/module_io/read_input_item_elec_stru.cpp

@@ -205,6 +205,18 @@ void ReadInput::item_elec_stru()
         };
         this->add_item(item);
     }
+    {
+        Input_Item item("nbands_mul");
+        item.annotation = "value to multiply the number of bands";
+        read_sync_double(input.nbands_mul);
+        item.check_value = [](const Input_Item& item, const Parameter& para) {
+            if (para.input.nbands_mul < 1.0)
+            {
+                ModuleBase::WARNING_QUIT("ReadInput", "nbands_mul should be greater than 1.0");
+            }
+        };
+        this->add_item(item);
+    }
     {
         Input_Item item("nelec");
         item.annotation = "input number of electrons";

source/module_parameter/input_parameter.h

@@ -75,6 +75,7 @@ struct Input_para
     std::string basis_type = "pw";     ///< xiaohui add 2013-09-01, for structural adjustment
     bool use_paw = false;              ///< whether to use PAW in pw calculation
     int nbands = 0;                    ///< number of bands
+    double nbands_mul = 1.2;           ///< multiplier for nbands
     double nelec = 0.0;                ///< total number of electrons
     double nelec_delta = 0.0;          ///< change in the number of total electrons
     double nupdown = 0.0;