Plots of the static structure factor S(q) of water as a function of momentum transfer q. The solid line shows results of first-principle calculations with configuration iteration (CI) wave functions including all single and double excitations (SDCI) [64]. The solid squares, diamonds, downward triangles, and upward triangles show S(q) values calculated with Eqns (32) and (33) from ELFs (q > 0) obtained with the FPA, SPA, SSPA, and EM methods, respectively. The solid circles represent S(q) values obtained with Eqn (32) from measured dynamic structure factors as a function of q by IXSS [59] with the corrections described in the text.