ROLE OF ELECTRONIC CORRELATION ON THE EQUATION OF STATE OF LITHIUM HYDRIDES

Three all-electron calculations of the relative P(V) equation of state (EOS) of LIH and LID are presented: (1) Hartree-Fock, (2) local densi ty approximation (LDA) using the Ceperley-Alder expression for correla tion, and (3) LDA using the Wigner expression for correlation. The res ults agree within 1% up to 10 GPa with the experimental values, implyi ng that the relative EOS in lithium hydrides depends only weakly on th e electronic correlation. The possibility of cancellation of errors wi th the LDA is discussed.