diff --git a/SFC_Torch/Fmodel.py b/SFC_Torch/Fmodel.py
index 1f95caa..85f901c 100644
--- a/SFC_Torch/Fmodel.py
+++ b/SFC_Torch/Fmodel.py
@@ -474,9 +474,10 @@ def calc_fsolvent(
         self,
         solventpct=None,
         gridsize=None,
-        dmin_mask=6.0,
-        Return=False,
+        dmin_mask=5.0,
         dmin_nonzero=3.0,
+        exponent=10.0,
+        Return=False,
     ):
         """
         Calculate the structure factor of solvent mask in a differentiable way
@@ -519,7 +520,7 @@ def calc_fsolvent(
         )
         rs_grid = reciprocal_grid(Hp1_array, Fp1_tensor, gridsize)
         self.real_grid_mask = rsgrid2realmask(
-            rs_grid, solvent_percent=solventpct
+            rs_grid, solvent_percent=solventpct, exponent=exponent, 
         )  # type: ignore
         if not self.HKL_array is None:
             self.Fmask_HKL = realmask2Fmask(self.real_grid_mask, self.HKL_array)
@@ -686,6 +687,13 @@ def init_scales(self, requires_grad=True):
         if hasattr(self, "Fo"):
             self.kmasks, self.kisos = self._init_kmask_kiso(requires_grad=requires_grad)
             self.uanisos = self._init_uaniso(requires_grad=requires_grad)
+            Fmodel = self.calc_ftotal()
+            Fmodel_mag = torch.abs(Fmodel)
+            self.r_work, self.r_free = r_factor(
+                self.Fo[~self.Outlier],
+                Fmodel_mag[~self.Outlier],
+                self.free_flag[~self.Outlier],
+            )
         else:
             self._set_scales(requires_grad)
 
@@ -801,7 +809,7 @@ def get_scales_lbfgs(
         ls_lr=0.1,
         r_lr=0.1,
         initialize=True,
-        verbose=True,
+        verbose=False,
     ):
         self._get_scales_lbfgs_LS(ls_steps, ls_lr, verbose, initialize)
         self._get_scales_lbfgs_r(r_steps, r_lr, verbose, initialize=False)
@@ -1005,10 +1013,11 @@ def calc_fsolvent_batch(
         self,
         solventpct=None,
         gridsize=None,
-        dmin_mask=6,
+        dmin_mask=5,
+        dmin_nonzero=3.0,
+        exponent=10.0,
         Return=False,
         PARTITION=100,
-        dmin_nonzero=3.0,
     ):
         """
         Should run after Calc_Fprotein_batch, calculate the solvent mask structure factors in batched manner
@@ -1058,7 +1067,7 @@ def calc_fsolvent_batch(
                 Hp1_array, Fp1_tensor_batch[start:end], gridsize, end - start
             )
             real_grid_mask = rsgrid2realmask(
-                rs_grid, solvent_percent=solventpct, Batch=True
+                rs_grid, solvent_percent=solventpct, exponent=exponent, Batch=True
             )  # type: ignore
             Fmask_batch_j = realmask2Fmask(real_grid_mask, HKL_array, end - start)
             if j == 0:
diff --git a/SFC_Torch/mask.py b/SFC_Torch/mask.py
index 07d20f9..1d0a82d 100644
--- a/SFC_Torch/mask.py
+++ b/SFC_Torch/mask.py
@@ -21,8 +21,8 @@ def reciprocal_grid(Hp1_array, Fp1_tensor, gridsize, batchsize=None):
     Return:
     Reciprocal space unit cell grid, as a torch.complex64 tensor
     """
-    grid = torch.zeros(gridsize, device=try_gpu(), dtype=torch.complex64)
-    tuple_index = tuple(torch.tensor(Hp1_array.T, device=try_gpu(), dtype=int))  # type: ignore
+    grid = torch.zeros(gridsize, device=Fp1_tensor.device, dtype=torch.complex64)
+    tuple_index = tuple(torch.tensor(Hp1_array.T, device=Fp1_tensor.device, dtype=int))  # type: ignore
     if batchsize is not None:
         for i in range(batchsize):
             Fp1_tensor_i = Fp1_tensor[i]
@@ -38,7 +38,7 @@ def reciprocal_grid(Hp1_array, Fp1_tensor, gridsize, batchsize=None):
         return grid
 
 
-def rsgrid2realmask(rs_grid, solvent_percent=0.50, scale=50, Batch=False):
+def rsgrid2realmask(rs_grid, solvent_percent=0.50, exponent=50.0, Batch=False):
     """
     Convert reciprocal space grid to real space solvent mask grid, in a
     fully differentiable way with torch
@@ -51,12 +51,12 @@ def rsgrid2realmask(rs_grid, solvent_percent=0.50, scale=50, Batch=False):
     solvent_percent: 0 - 1 float
         The approximate volume percentage of solvent in the system, to generate the cutoff
 
-    scale: int/float
+    exponent: int/float
         The scale used in sigmoid function, to make the distribution binary
 
     Return:
     -------
-    tf.float32 tensor
+    torch.float32 tensor
     The solvent mask grid in real space, solvent voxels have value close to 1, while protein voxels have value close to 0.
     """
     real_grid = torch.real(torch.fft.fftn(rs_grid, dim=(-3, -2, -1)))
@@ -65,7 +65,7 @@ def rsgrid2realmask(rs_grid, solvent_percent=0.50, scale=50, Batch=False):
         CUTOFF = torch.quantile(real_grid_norm[0], solvent_percent)
     else:
         CUTOFF = torch.quantile(real_grid_norm, solvent_percent)
-    real_grid_mask = torch.sigmoid((CUTOFF - real_grid_norm) * 50)
+    real_grid_mask = torch.sigmoid((CUTOFF - real_grid_norm) * exponent)
     return real_grid_mask
 
 
@@ -88,7 +88,7 @@ def realmask2Fmask(real_grid_mask, H_array, batchsize=None):
     Solvent mask structural factor corresponding to the HKL list in H_array
     """
     Fmask_grid = torch.fft.ifftn(real_grid_mask, dim=(-3, -2, -1), norm="forward")
-    tuple_index = tuple(torch.tensor(H_array.T, device=try_gpu(), dtype=int))  # type: ignore
+    tuple_index = tuple(torch.tensor(H_array.T, device=Fmask_grid.device, dtype=int))  # type: ignore
     if batchsize is not None:
         Fmask = Fmask_grid[(slice(None), *tuple_index)]
     else: