I have the following code where I’m trying to encode a vector of 4 features into a 2-qubit quantum state on the qiskit.aer simulator backend.

```
import pennylane as qml
from pennylane import numpy as np
import pennylane_qiskit as pqis
import math,qiskit
dev = qml.device('qiskit.aer', wires=2, backend = 'statevector_simulator')
x = np.array([0.53896774,0.79503606,0.27826503,0.]) # n qubits to encode 2^n features
#x = np.array([1,0,0,0])
@qml.qnode(dev)
def test(x):
qml.QubitStateVector(x,wires = [0,1])
return qml.expval(qml.PauliZ(0))
print(test(x))
```

This outputs the following **error**:

```
QiskitError: 'Sum of amplitudes-squared does not equal one.'
```

I have obviously checked that this is True:

```
math.isclose(sum(np.absolute(x) ** 2), 1.0,abs_tol=1e-7)
```

could it be qiskit’s tolerance eps value?

**Qiskit version** 0.9.0

**Pennylane qiskit plugin** 0.5.1

Also I’m getting the expectation value of the Pauli Z opeartor of the first qubit , but I’m rather interested on the marginal probabilities of quantum state, is there a way to extract that from the quantum node dev?

Thank you very much pennylane community!