d}}",
                vxc: "{v_\\xc}",
                // symrel
                Ri: "{\\mcR^{-1}}",
                Rit: "{\\mcR^{-1\\tau}}",
                // symrec
                Si: "{\\mcS^{-1}}}",
                Sit: "{\\Si^\\tau}}",
                // partial and functional derivative.
                PDER: ["{\\dfrac{\\partial #1}{\\partial #2}}", 2],
                FDER: ["{\\dfrac{\\delta #1}{\\delta #2}}", 2],
                // PAW
                tPsi: "{\\tilde\\Psi}",
                tps