Computational probing of all-boron Li2nB2nH2n+2 polyenes

► We tested if Li2nB2nH2n+2 (n = 2-7) chains are viable species. ► The global minimum structure of Li4B4H6 has the trans-cisoid kernel of B atoms. ► The trans-cisoid form of Li2nB2nH2n+2 is much more stable than the cis-transoid form. ► Li2nB2nH2n+2 (n = 2-7) with the trans-cisoid kernel of B atoms are minima on the PES.