An innovative type of lithium decahydroborate (Li@B10H14) complex with a basketlike complexant of decaborane (B10H14) has been designed using quantum mechanical methods. As Li atom binds in a handle fashion to terminal electrophilic boron atoms of the decaborane basket, its NBO charge q (Li) is found to be 0.876, close to +1. This shows that the Li atom has been ionized to form a cation and an anion at the open end of B10H14. The most fascinating feature of this Li doping is its loosely bound valence electron, which has been pulled into the cavity of the B10H14 basket and become diffuse by the electron-deficient morphological features of the open end of the B10H14 basket. Strikingly, the first hyperpolarizability (beta(0)) of Li@B10H14 is about 340 times larger than that of B10H14, computed to be 23 075 au (199 x 10(-30) esu) and 68 au, respectively. Besides this, the intercalation of the Li atom to the B10H14 basket brings some distinctive changes in its Raman, B-11 NMR, and UV-vis spectra along with its other electronic properties that might be used by the experimentalists to identify this novel kind of Li@B10H14 complex with a large electro-optical response. This study may evoke the possibility to explore a new thriving area, i.e., alkali metal-boranes for NLO application.