Refactor&Docs: Simplify deepks_bandgap realization and add input value checks. (#6241)

* Add value check for deepks_bandgap_range.

* Simplify code for deepks_bandgap labels.

* Combine deepks_bandgap=1&3.

* Correct a mistake in doc.

Author: ErjieWu

docs/advanced/input_files/input-main.md

@@ -195,7 +195,7 @@
     - [bessel\_descriptor\_smooth](#bessel_descriptor_smooth)
     - [bessel\_descriptor\_sigma](#bessel_descriptor_sigma)
     - [deepks\_bandgap](#deepks_bandgap)
-    - [deepks\_bandgap\_range](#deepks_bandgap_range)
+    - [deepks\_band\_range](#deepks_band_range)
     - [deepks\_v\_delta](#deepks_v_delta)
     - [deepks\_out\_unittest](#deepks_out_unittest)
   - [OFDFT: orbital free density functional theory](#ofdft-orbital-free-density-functional-theory)
@@ -2149,20 +2149,19 @@ Warning: this function is not robust enough for the current version. Please try
 - **Availability**: numerical atomic orbital basis and `deepks_scf` is true
 - **Description**: include bandgap label for DeePKS training
   - 0: Don't include bandgap label
-  - 1: Include HOMO and LOMO for bandgap label
-  - 2: Include multiple bandgap label (see [deepks\_bandgap\_range](#deepks_bandgap_range) for more details)
-  - 3: Include target bandgap label (see [deepks\_bandgap\_range](#deepks_bandgap_range) for more details)
-  - 4: For systems containing H atoms only, HOMO is defined as the max occupation expect H atoms and the bandgap label is the energy between (HOMO, HOMO + 1)
+  - 1: Include target bandgap label (see [deepks\_band\_range](#deepks_band_range) for more details)
+  - 2: Include multiple bandgap label (see [deepks\_band\_range](#deepks_band_range) for more details)
+  - 3: For systems containing H atoms only, HOMO is defined as the max occupation expect H atoms and the bandgap label is the energy between HOMO and (HOMO + 1)
 - **Default**: 0
 
-### deepks_bandgap_range
+### deepks_band_range
 
 - **Type**: Int*2
-- **Availability**: numerical atomic orbital basis, `deepks_scf` is true, and `deepks_bandgap` is 2 or 3
-- **Description**: 
-  - `deepks_bandgap` is 2: Bandgap labels are energies between (LUMO + deepks_bandgap_range[0], HOMO), (LUMO + deepks_bandgap_range[0] + 1, HOMO), ..., (LUMO + deepks_bandgap_range[1], HOMO) except (HOMO, HOMO)
-  - `deepks_bandgap` is 3: Bandgap label is the energy between (LUMO + deepks_bandgap_range[0], LUMO + deepks_bandgap_range[1])
-- **Default**: 0 0
+- **Availability**: numerical atomic orbital basis, `deepks_scf` is true, and `deepks_bandgap` is 1 or 2
+- **Description**: The first value should not be larger than the second one and the meaning differs in different cases below
+  - `deepks_bandgap` is 1: Bandgap label is the energy between `LUMO + deepks_band_range[0]` and `LUMO + deepks_band_range[1]`. If not set, it will calculate energy between HOMO and LUMO states.
+  - `deepks_bandgap` is 2: Bandgap labels are energies between HOMO and all states in range [`LUMO + deepks_band_range[0]`, `LUMO + deepks_band_range[1]`] (Thus there are `deepks_band_range[1] - deepks_band_range[0] + 1` bandgaps in total). If HOMO is included in the setting range, it will be ignored since it will always be zero and has no valuable messages (`deepks_band_range[1] - deepks_band_range[0]` bandgaps in this case). *NOTICE: The set range can be greater than, less than, or include the value of HOMO. In the bandgap label, we always calculate the energy of the state in the set range minus the energy of HOMO state, so the bandgap can be negative if the state is lower than HOMO.*
+- **Default**: -1 0
 
 ### deepks_v_delta
 

source/module_hamilt_lcao/module_deepks/LCAO_deepks_interface.cpp

@@ -19,13 +19,13 @@ void ReadInput::item_deepks()
         read_sync_bool(input.deepks_scf);
         item.check_value = [](const Input_Item& item, const Parameter& para) {
 #ifndef __DEEPKS
-            if (PARAM.inp.deepks_scf || PARAM.inp.deepks_out_labels || PARAM.inp.deepks_bandgap
-                || PARAM.inp.deepks_v_delta)
+            if (para.input.deepks_scf || para.input.deepks_out_labels || para.input.deepks_bandgap
+                || para.input.deepks_v_delta)
             {
                 ModuleBase::WARNING_QUIT("Input_conv", "please compile with DeePKS");
             }
 #endif
-            // if (!PARAM.inp.deepks_scf && PARAM.inp.deepks_out_labels == 1)
+            // if (!para.input.deepks_scf && para.input.deepks_out_labels == 1)
             // {
             //     ModuleBase::WARNING_QUIT("Input_conv", "deepks_out_labels = 1 requires deepks_scf = 1");
             // }
@@ -58,6 +58,29 @@ void ReadInput::item_deepks()
             para.input.deepks_band_range[1] = std::stod(item.str_values[1]);
         };
         sync_intvec(input.deepks_band_range, 2, 0);
+        item.check_value = [](const Input_Item& item, const Parameter& para) {
+            if (para.input.deepks_bandgap == 1)
+            {
+                if (para.input.deepks_band_range[0] >= para.input.deepks_band_range[1])
+                {
+                    ModuleBase::WARNING_QUIT("ReadInput", "deepks_band_range[0] must be smaller than deepks_band_range[1] for deepks_bandgap = 1.");
+                }
+            }
+            else if (para.input.deepks_bandgap == 2)
+            {
+                if (para.input.deepks_band_range[0] > para.input.deepks_band_range[1])
+                {
+                    ModuleBase::WARNING_QUIT("ReadInput", "deepks_band_range[0] must be no more than deepks_band_range[1] for deepks_bandgap = 2.");
+                }
+            }
+            else
+            {
+                if (para.input.deepks_band_range[0] != -1 || para.input.deepks_band_range[1] != 0)
+                {
+                    ModuleBase::WARNING("ReadInput", "deepks_band_range is used for deepks_bandgap = 1/2. Ignore its setting for other cases.");
+                }
+            } 
+        };
         this->add_item(item);
     }
     {

source/module_io/read_input_item_deepks.cpp

@@ -265,7 +265,7 @@ struct Input_para
     bool deepks_scf = false;           ///< (need libnpy and libtorch) if set to true, a trained model
                                        ///< would be needed to calculate V_delta and F_delta
     int deepks_bandgap = 0;       ///< for bandgap label. QO added 2021-12-15
-    std::vector<int> deepks_band_range = {0, 0}; ///< the range of bands to calculate bandgap
+    std::vector<int> deepks_band_range = {-1, 0}; ///< the range of bands to calculate bandgap
     int deepks_v_delta = 0;            ///< for v_delta label. xuan added
     bool deepks_equiv = false;         ///< whether to use equivariant version of DeePKS
     bool deepks_out_unittest = false;  ///< if set to true, prints intermediate quantities that shall

source/module_parameter/input_parameter.h

@@ -21,3 +21,4 @@ deepks_scf          1
 deepks_model        ../Model_ProjOrb/model_lda_pbe_18.ptg
 deepks_out_labels   1
 deepks_bandgap      1
+deepks_band_range   -1 0

tests/09_DeePKS/103_NO_GO_deepks_bandgap/INPUT

@@ -21,4 +21,3 @@ deepks_scf          1
 deepks_model        ../Model_ProjOrb/model_lda_pbe_18.ptg
 deepks_out_labels   1
 deepks_bandgap      3
-deepks_band_range   -1 0