def METHOD_NAME():
    global cell, nao
    L = 5.
    n = 3
    cell = pgto.Cell()
    cell.a = numpy.diag([L,L,L])
    cell.mesh = numpy.array([n,n,n])
    cell.atom = '''He    3.    2.       3.
                   He    1.    1.       1.'''
    cell.basis = 'ccpvdz'
    cell.verbose = 0
    cell.build(0,0)
    nao = cell.nao_nr()