STABILITY STUDIES OF THE AL-LI-CU ICOSAHEDRAL QUASI-CRYSTAL BY MEANS OF THE EMBEDDED-ATOM METHOD

Total energies of the T2-Al6Li3Cu icosahedral quasicrystal and its cry stalline approximant are calculated by means of the embedded-atom meth od and are compared with the fictitious Al-Li-Cu solid solutions and m ixtures. For such a calculation. the real atomic structure of the icos ahedral T2-Al6Li3Cu phase is obtained by the projection method and spe cial cubic spline knots for the embedding function F(Li)(Q) are select ed to overcome the difficulty that the local electron density in Al-Li -Cu alloys is much larger than that in the pure Li crystal. The result s show that both quasicrystalline T2-Al6Li3Cu and crystalline R-Al5Li3 Cu are stable phases compared with the fictitious corresponding solid solutions and mixtures of pure Al, Li, and Cu crystals. These results are consistent with the experiments within the theoretical error.