The pair(s) of lanthanide ions whose ground state term symbols have same spin multiplicity \((2S+1)\) and orbital angular momentum \((L)\), but different spin-orbit coupling \((J)\) is(are)
(Given: Atomic number: \(\mathrm{Nd}=60\); \(\mathrm{Pm}=61\); \(\mathrm{Ho}=67\); \(\mathrm{Er}=68\))