The molecular positronium (sometimes also denoted as di-positronium) was the multi-electron bound state composed of e+e-e+e-, where the electromagnetic interaction is the underlying driving force.Although its existence was predicted as early as in 1947 [1], it remained elusive until it was produced experimentally in 2007 [2].One may wonder whether there exists the analogue of the di-positronium in Quantum Chromodynamics, which is the tetraquark state with the flavor configurations q(q)q(q).Very recently, the LHCb Collaboration observed distinct structures with the cc(c)(c) (two charm quarks and two anti-charm quarks) in the J/ψ-pair mass spectrum [3].They reported a broad structure ranging from 6.2 to 6.8 GeV and a narrow structure at around 6.9 GeV with a global significance of more than 5σ.Let's denote it as T4c.