Get Structure using Transformation matrix

[prnvrvs]

Begineer Question

import pymatgen.core as pmg
from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
import numpy as np
Al=pmg.Structure.from_spacegroup(225,pmg.Lattice.cubic(4.05),["Al"],[[0,0,0]])
finder = SpacegroupAnalyzer(Al)

mat=finder.get_conventional_to_primitive_transformation_matrix()

How to get primitive unit cell of Al using transformation matrix (mat) equivalent to Al.get_primitive_structure()

Al_prim=Al.copy()
Affine_mat=np.hstack([np.vstack([mat,[0,0,0]]),[[0],[0],[0],[1]]]
Al_prim.apply_operation(pmg.operations.SymmOp(Affine_mat))

The above code is giving 4 atoms similar to conventional but correct cell dimension.

Thanks