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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def rhombohedral(a: float, alpha: float):
 """ Convenience constructor for a rhombohedral lattice. Args: a (float):
 *a* lattice parameter of the rhombohedral cell. alpha (float):
 Angle for the rhombohedral lattice in degrees. Returns: Rhombohedral lattice of dimensions a x a x a. """

        return Lattice.from_parameters(a, a, a, alpha, alpha, alpha)