def _check90deg(pd):
    """Return True if the Euler angles are 0,90,180, etc"""
    psi, phi, theta = int(pd['psi']), int(pd['phi']), int(pd['theta'])
    if psi % 90 == 0 and phi % 90 == 0 and theta % 90 == 0:
        return True
    else:
        return False