def METHOD_NAME():
    global mol, pmol, mf_lda, mf_gga, nstates
    mol = gto.Mole()
    mol.verbose = 5
    mol.output = '/dev/null'
    mol.atom = [
        ['H' , (0. , 0. , 1.804)],
        ['F' , (0. , 0. , 0.)], ]
    mol.unit = 'B'
    mol.charge = 2
    mol.spin = 2
    mol.basis = '631g'
    mol.build()
    pmol = mol.copy()
    mf_lda = dft.UKS(mol).set(xc='LDA,', conv_tol=1e-12)
    mf_lda.kernel()
    mf_gga = dft.UKS(mol).set(xc='b88,', conv_tol=1e-12)
    mf_gga.kernel()
    nstates = 5 # to ensure the first 3 TDSCF states are converged