Information

• Qiskit Terra version:
  {'qiskit-terra': '0.14.2',
  'qiskit-aer': '0.5.2',
  'qiskit-ignis': '0.3.3',
  'qiskit-ibmq-provider': '0.7.2',
  'qiskit-aqua': '0.7.3',
  'qiskit': '0.19.6'}

• Python version:
  3.7.6

• Operating system:
  Mac OSX

What is the current behavior?

rz gate produces different states when the control and target qubit is switched. Symmetry is not preserved.

Steps to reproduce the problem

qc = QuantumCircuit(2)
qc.h(i)
qc.crz (PI/4, 0, 1)

print state vector

replace the last line with

qc.crz (PI/4, 1, 0)

print the state again

What is the expected behavior?

Switching of target qubit and control qubit should result in the same state vector

Suggested solutions

I think the issue is using theta/2 instead of theta which is inconsistent with rz gate behaviour which doesn't use theta/2