Blender Python Create Cube and add Material

bpy.ops.mesh.primitive_cube_add(enter_editmode=False, align='WORLD', location=(9,15, 0), scale=(.5, .5, .5))
mat = bpy.data.materials.new('material_TEST1')
mat.use_nodes = True
bpy.data.materials["material_TEST1"].node_tree.nodes["Principled BSDF"].inputs[0].default_value = (0.4601, 0.228801, 0.450716, 1)
bpy.context.object.active_material = mat