'Wigner D-function.
Returns an instance of the WignerD class corresponding to the Wigner-D
function specified by the parameters.
Parameters
j : Number
Total angular momentum
m : Number
Eigenvalue of angular momentum along axis after rotation
mp : Number
Eigenvalue of angular momentum along rotated axis
alpha : Number, Symbol
First Euler angle of rotation
beta : Number, Symbol
Second Euler angle of rotation
gamma : Number, Symbol
Third Euler angle of rotation
Examples
Return the Wigner-D matrix element for a defined rotation, both
numerical and symbolic:
>>> from sympy.physics.quantum.spin import Rotation
>>> from sympy import pi, symbols
>>> alpha, beta, gamma = symbols(\'alpha beta gamma\')
>>> Rotation.D(1, 1, 0,pi, pi/2,-pi)
WignerD(1, 1, 0, pi, pi/2, -pi)
See Also
WignerD: Symbolic Wigner-D function'

@classmethod
def D(cls, j, m, mp, alpha, beta, gamma):

    return WignerD(j, m, mp, alpha, beta, gamma)
