diff --git a/pyxtal/optimize/common.py b/pyxtal/optimize/common.py
index c7b95d7..8389c12 100644
--- a/pyxtal/optimize/common.py
+++ b/pyxtal/optimize/common.py
@@ -236,9 +236,11 @@ def optimizer(
     for i, calculator in enumerate(calculators):
         if calculator == "CHARMM":
             if i == 0:
-                calc = CHARMM(struc, tag, steps=[1000], atom_info=atom_info)
-                calc.run()#clean=False); import sys; sys.exit()
+                calc = CHARMM(struc, tag, steps=[1000], atom_info=atom_info, debug=True)
+                calc.run() #clean=False); import sys; sys.exit()
                 # print("CCCCCC", calc.optimized); import sys; sys.exit()
+                #print(calc.error)
+                #print(calc.struc.lattice, calc.error, calc.structure.energy)
                 if calc.error:
                     os.chdir(cwd)
                     return None
@@ -294,7 +296,7 @@ def optimizer(
         else:
             struc = calc.structure
             struc.resort()
-
+    print(struc.lattice, calc.structure.energy)
     os.chdir(cwd)
 
     # density should not be too small
diff --git a/requirements.txt b/requirements.txt
index 5d1d314..f3a8fcd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -38,7 +38,7 @@ networkx==3.3
     # via
     #   pyxtal (setup.py)
     #   pymatgen
-numpy==1.26.4
+numpy==2.0.0
     # via
     #   pyxtal (setup.py)
     #   ase
diff --git a/setup.py b/setup.py
index b7ce63e..16b1419 100755
--- a/setup.py
+++ b/setup.py
@@ -66,7 +66,7 @@ def run(self):
         "networkx>=2.3",
         "ase>=3.23.0",
         "scipy>=1.7.3",
-        "numpy>=1.26,<2",  # prevent the use of numpy2
+        #"numpy>=1.26,<2",  # prevent the use of numpy2
         "vasprun-xml>=1.0.4",  # prevent the use of numpy2
         "importlib_metadata>=1.4",
         "typing-extensions>=4.12",