update readme

Author: QG-phy

README.md

@@ -56,10 +56,10 @@ Installing **DeePTB** is straightforward. We recommend using a virtual environme
 3. Navigate to the root directory and install DeePTB:
    ```bash
    cd DeePTB
-   BUILD_FORTRAN=ON USE_INTEL=ON USE_OPENMP=ON pip install .
+   BUILD_FORTRAN=ON pip install .
    ```
-   Note: by default, the optical response module is not installed. To install it, you need to set the `BUILD_FORTRAN=ON` flag. The `USE_INTEL=ON` flag is used to enable the Intel MKL library, and the `USE_OPENMP=ON` flag is used to enable OpenMP parallelization. Both `USE_INTEL` and `USE_OPENMP` are `ON` by default.
-
+   Note: by default, the optical response module is not installed. To install it, you need to set the `BUILD_FORTRAN=ON` flag. By default we set the CMakeList.txt to use the intel compiler with openmp enabled. If you want to use other compilers, you need to modify the CMakeList.txt file.
+   
 ## Usage
 For a comprehensive guide and usage tutorials, visit [our documentation website](https://deeptb.readthedocs.io/en/latest/).
 

dptb/postprocess/optical/optical_cond.py

@@ -2,11 +2,10 @@
 import numpy as np
 from dptb.data import AtomicDataDict
 from dptb.data import AtomicData
-
+import sys
 import torch
 from dptb.nn.hr2hk import HR2HK
 from dptb.nn.hr2dhk import Hr2dHk
-from dptb.postprocess.fortran import ac_cond as acdf2py
 import math
 from dptb.utils.make_kpoints import  kmesh_sampling_negf
 import time
@@ -15,6 +14,10 @@
 from ase.io import read
 import matplotlib.pyplot as plt
 
+try:
+    from dptb.postprocess.fortran import ac_cond as acdf2py
+except ImportError:
+    acdf2py = None
 
 log = logging.getLogger(__name__)
 
@@ -32,6 +35,9 @@ def __init__(self, model:torch.nn.Module, results_path: str=None, use_gui: bool=
         self.use_gui = use_gui
         self.device = device
         os.makedirs(results_path, exist_ok=True)
+        if acdf2py is None:
+            log.warning('ac_cond_f is not available, please install the fortran code to calculate the AC conductivity')
+            sys.exit(1)
 
     def get_accond(self,
                         struct,