diff --git a/src/quanguru/QuantumToolbox/evolution.py b/src/quanguru/QuantumToolbox/evolution.py
index 1f99747c..0c03c984 100644
--- a/src/quanguru/QuantumToolbox/evolution.py
+++ b/src/quanguru/QuantumToolbox/evolution.py
@@ -305,7 +305,7 @@ def _preSO(operator: Matrix, identity: Matrix = None) -> Matrix:
 
     if identity is None:
         identity = sp.identity(operator.shape[0], format="csc")
-    pre = sp.kron(identity, operator, format='csc')
+    pre = sp.kron(operator, identity, format='csc')
     return pre if sp.issparse(operator) else pre.A
 
 def _postSO(operator: Matrix, identity: Matrix = None) -> Matrix:
@@ -338,7 +338,7 @@ def _postSO(operator: Matrix, identity: Matrix = None) -> Matrix:
 
     if identity is None:
         identity = sp.identity(operator.shape[0], format="csc")
-    pos = sp.kron(operator.transpose(), identity, format='csc')
+    pos = sp.kron(identity, operator.transpose(), format='csc')
     return pos if sp.issparse(operator) else pos.A
 
 def _prepostSO(operatorA: Matrix, operatorB: Optional[Matrix] = None) -> Matrix:
@@ -371,7 +371,7 @@ def _prepostSO(operatorA: Matrix, operatorB: Optional[Matrix] = None) -> Matrix:
     """
     if operatorB is None:
         operatorB = operatorA
-    prepost = sp.kron(operatorB.transpose(), operatorA, format='csc')
+    prepost = sp.kron(operatorA, operatorB.transpose(), format='csc')
     return prepost if sp.issparse(operatorA) else prepost.A
 
 def evolveOpen(initialState, totalTime, timeStep: float = 1.0, Hamiltonian: Optional[Matrix] = None,# pylint: disable=dangerous-default-value,unsubscriptable-object,too-many-arguments # noqa: E501
diff --git a/src/quanguru/QuantumToolbox/states.py b/src/quanguru/QuantumToolbox/states.py
index 04cec2e3..b37c74e2 100644
--- a/src/quanguru/QuantumToolbox/states.py
+++ b/src/quanguru/QuantumToolbox/states.py
@@ -542,7 +542,7 @@ def mat2Vec(denMat: Matrix) -> Matrix: # pylint: disable=invalid-name
      [1]]
     """
 
-    return denMat.T.reshape(np.prod(np.shape(denMat)), 1)
+    return denMat.reshape(np.prod(np.shape(denMat)), 1)
 
 def vec2Mat(vec: Matrix) -> Matrix: # pylint: disable=invalid-name
     r"""
@@ -575,7 +575,7 @@ def vec2Mat(vec: Matrix) -> Matrix: # pylint: disable=invalid-name
 
     a = vec.shape
     n = int(np.sqrt(a[0]))
-    mat = vec.reshape((n, n)).T
+    mat = vec.reshape((n, n))
     return mat
 
 def BellStates(bs: str = 'Phi+', sparse: bool = True) -> Matrix: