Support binary LCAO wavefunction input

docs/advanced/elec_properties/wfc.md

@@ -7,12 +7,14 @@ ABACUS is able to output electron wave functions in both PW and LCAO basis calcu
 To output wave functions in G-space, add one of the following keywords to the `INPUT` file while performing SCF calculation:
 - **PW basis**: Set [`out_wfc_pw`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#out-wfc-pw) to `1`. Output file format: `wfs[spin]k[kpoint]_pw.txt`, where `[spin]` is the spin channel index, and `[kpoint]` the k-point index.
 
-- **LCAO basis**: Set [`out_wfc_lcao`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#out-wfc-lcao) to `1`.  
-  - **Multi-k calculations**: Generates multiple files `wfs[spin]k[kpoint]_nao.txt`.
-  - **Gamma-only calculations**: `wfs[spin]_nao.txt` instead.
+- **LCAO basis**: Set [`out_wfc_lcao`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#out-wfc-lcao) to `1` for text or `2` for binary output.
+  - **Multi-k calculations**: Generates multiple files `wfs[spin]k[kpoint]_nao.txt` or `.dat`.
+  - **Gamma-only calculations**: Generates `wfs[spin]_nao.txt` or `.dat` instead.
+
+To reuse LCAO coefficients, set `init_wfc file`, point `read_file_dir` to the coefficient files, and set `read_wfc_lcao` to `1` for text or `2` for binary input. The selected extension is required; there is no automatic format fallback.
 
 ## Wave Function in Real Space
 
 One can also choose to output real-space wave functions with the keyword [`out_wfc_norm`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#out-wfc-norm) or [`out_wfc_re_im`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#out-wfc-re-im).
 
-Notice: When the [`basis_type`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#basis-type) is `lcao`, only `get_wf` [`calculation`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#calculation) is effective. An example is [examples/11_wfc/lcao_ienvelope_Si2](https://github.com/deepmodeling/abacus-develop/tree/develop/examples/11_wfc/lcao_ienvelope_Si2).
+Notice: When the [`basis_type`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#basis-type) is `lcao`, only `get_wf` [`calculation`](https://abacus-rtd.readthedocs.io/en/latest/advanced/input_files/input-main.html#calculation) is effective. An example is [examples/11_wfc/lcao_ienvelope_Si2](https://github.com/deepmodeling/abacus-develop/tree/develop/examples/11_wfc/lcao_ienvelope_Si2).

docs/advanced/input_files/input-main.md

@@ -19,6 +19,7 @@
     - [latname](#latname)
     - [assume\_isolated](#assume_isolated)
     - [init\_wfc](#init_wfc)
+    - [read\_wfc\_lcao](#read_wfc_lcao)
     - [init\_chg](#init_chg)
     - [init\_vel](#init_vel)
     - [mem\_saver](#mem_saver)
@@ -737,14 +738,28 @@
 
   - atomic: from atomic pseudo wave functions. If they are not enough, other wave functions are initialized with random numbers.
   - atomic+random: add small random numbers on atomic pseudo-wavefunctions
-  - file: from binary files wf*.dat, which are output by setting out_wfc_pw to 2.
+  - file: from wave function coefficient files. For PW calculations, binary `wf*.dat` files are generated by setting `out_wfc_pw` to 2. For LCAO calculations, the text or binary format is selected by `read_wfc_lcao` and generated by setting `out_wfc_lcao` to the corresponding value.
   - random: random numbers
   - nao: from numerical atomic orbitals. If they are not enough, other wave functions are initialized with random numbers.
   - nao+random: add small random numbers on numerical atomic orbitals
 
   > Note: Only the file option is useful for the lcao basis set, which is mostly used when calculation is set to get_wf and get_pchg.
 - **Default**: atomic
 
+### read_wfc_lcao
+
+- **Type**: Integer
+- **Availability**: *[`basis_type`](#basis_type)==lcao*
+- **Description**: The file format used when reading LCAO wave function coefficients.
+
+  Available options are:
+
+  - 1: text files (`.txt`) generated by setting `out_wfc_lcao` to 1.
+  - 2: binary files (`.dat`) generated by setting `out_wfc_lcao` to 2.
+
+  The selected format is used directly; ABACUS does not automatically detect or fall back to the other format. Only independent wave function files are supported, not files accumulated with `out_app_flag`.
+- **Default**: 1
+
 ### init_chg
 
 - **Type**: String

docs/advanced/scf/initialization.md

@@ -21,4 +21,4 @@ Atomic wave function is read from pseudopotential file under keyword `PP_PSWFC`,
 
 When `basis_type=lcao`, we further support reading of initial wavefunction by setting `init_wfc` to `file`.
 In LCAO code, wave function is used to initialize density matrix and real-space charge density.
-For such purpose, a file containing wavefunction must be prepared. Such files can be generated from previous calculations with [`out_wfc_lcao 1`](../elec_properties/wfc.md).
+For such purpose, files containing wavefunction coefficients must be prepared. They can be generated by a previous calculation with [`out_wfc_lcao 1`](../elec_properties/wfc.md) for text files or `out_wfc_lcao 2` for binary files. Set `read_wfc_lcao` to the same value when reading them; ABACUS does not automatically switch between formats.

docs/parameters.yaml

@@ -168,7 +168,7 @@ parameters:
       Available options are:
       * atomic: from atomic pseudo wave functions. If they are not enough, other wave functions are initialized with random numbers.
       * atomic+random: add small random numbers on atomic pseudo-wavefunctions
-      * file: from binary files wf*.dat, which are output by setting out_wfc_pw to 2.
+      * file: from wave function coefficient files. For PW calculations, binary `wf*.dat` files are generated by setting `out_wfc_pw` to 2. For LCAO calculations, the text or binary format is selected by `read_wfc_lcao` and generated by setting `out_wfc_lcao` to the corresponding value.
       * random: random numbers
       * nao: from numerical atomic orbitals. If they are not enough, other wave functions are initialized with random numbers.
       * nao+random: add small random numbers on numerical atomic orbitals
@@ -177,6 +177,20 @@ parameters:
     default_value: atomic
     unit: ""
     availability: ""
+  - name: read_wfc_lcao
+    category: System variables
+    type: Integer
+    description: |
+      The file format used when reading LCAO wave function coefficients.
+
+      Available options are:
+      * 1: text files (`.txt`) generated by setting `out_wfc_lcao` to 1.
+      * 2: binary files (`.dat`) generated by setting `out_wfc_lcao` to 2.
+
+      The selected format is used directly; ABACUS does not automatically detect or fall back to the other format. Only independent wave function files are supported, not files accumulated with `out_app_flag`.
+    default_value: "1"
+    unit: ""
+    availability: basis_type==lcao
   - name: init_chg
     category: System variables
     type: String

source/source_esolver/esolver_ks_lcao_tddft.cpp

@@ -114,6 +114,7 @@ void ESolver_KS_LCAO_TDDFT<TR, Device>::before_all_runners(BaseCell& basecell, c
                                     this->kv.ik2iktot,
                                     this->kv.get_nkstot(),
                                     this->inp_->nspin,
+                                    this->inp_->read_wfc_lcao,
                                     0,
                                     TD_info::estep_shift))
         {

source/source_esolver/esolver_lr_lcao_tddft.cpp

@@ -805,6 +805,7 @@ void ModuleESolver::ESolver_LR<T, TR>::read_ks_wfc()
 				this->kv.ik2iktot,
 				this->kv.get_nkstot(),
                 this->inp_->nspin,
+				this->inp_->read_wfc_lcao,
 				/*skip_bands=*/this->nocc_max - this->nocc_in)) {
         ModuleBase::WARNING_QUIT("ESolver_LR", "read ground-state wavefunction failed.");
     }

source/source_io/module_parameter/input_parameter.h

@@ -46,6 +46,7 @@ struct Input_para
     double erf_sigma = 0.1;             ///< the width of the energy step for reciprocal vectors
     int fft_mode = 0;                   ///< fftw mode 0: estimate, 1: measure, 2: patient, 3: exhaustive
     std::string init_wfc = "atomic";    ///< "file","atomic","random"
+    int read_wfc_lcao = 1;              ///< LCAO wavefunction input format: 1 text, 2 binary
     int pw_seed = 0;                    ///< random seed for initializing wave functions
     std::string init_chg = "atomic";    ///< "file","atomic"
     bool dm_to_rho = false;             ///< read density matrix from npz format and calculate charge density

source/source_io/module_parameter/read_inp_sys.cpp

@@ -448,7 +448,7 @@ Theory: G. Makov and M. C. Payne, Phys. Rev. B 51, 4014 (1995).)";
 Available options are:
 * atomic: from atomic pseudo wave functions. If they are not enough, other wave functions are initialized with random numbers.
 * atomic+random: add small random numbers on atomic pseudo-wavefunctions
-* file: from binary files wf*.dat, which are output by setting out_wfc_pw to 2.
+* file: from wave function coefficient files. For PW calculations, binary `wf*.dat` files are generated by setting `out_wfc_pw` to 2. For LCAO calculations, the text or binary format is selected by `read_wfc_lcao` and generated by setting `out_wfc_lcao` to the corresponding value.
 * random: random numbers
 * nao: from numerical atomic orbitals. If they are not enough, other wave functions are initialized with random numbers.
 * nao+random: add small random numbers on numerical atomic orbitals
@@ -474,6 +474,30 @@ Available options are:
         read_sync_string(input.init_wfc);
         this->add_item(item);
     }
+    {
+        Input_Item item("read_wfc_lcao");
+        item.annotation = "LCAO wave function input format: 1 text, 2 binary";
+        item.category = "System variables";
+        item.type = "Integer";
+        item.description = R"(The file format used when reading LCAO wave function coefficients.
+
+Available options are:
+* 1: text files (`.txt`) generated by setting `out_wfc_lcao` to 1.
+* 2: binary files (`.dat`) generated by setting `out_wfc_lcao` to 2.
+
+The selected format is used directly; ABACUS does not automatically detect or fall back to the other format. Only independent wave function files are supported, not files accumulated with `out_app_flag`.)";
+        item.default_value = "1";
+        item.unit = "";
+        item.set_availability("basis_type==lcao");
+        read_sync_int(input.read_wfc_lcao);
+        item.check_value = [](const Input_Item& item, const Parameter& para) {
+            if (para.input.read_wfc_lcao != 1 && para.input.read_wfc_lcao != 2)
+            {
+                ModuleBase::WARNING_QUIT("ReadInput", "read_wfc_lcao should be 1 or 2");
+            }
+        };
+        this->add_item(item);
+    }
     {
         Input_Item item("init_chg");
         item.annotation = "start charge is from 'atomic' or file";