X-Ray Determination of the Static Structure Factor of Liquid Na and K

Highly accurate x-ray diffraction measurements are presented for the static structure factor $a\left(q\right)\mathrm{}$ for liquid Na (at 100 and 200 °C) and liquid K (at 65 and 135 °C). A detailed error analysis is presented showing that the over-all root-mean-square error in $a\left(q\right)\mathrm{}$ never exceeds 2.5% for any value of the momentum transfer $q$ and the relative root-mean-square error in $a\left(q\right)\mathrm{}$ between different temperatures is always less than 1.5%. We discuss and demonstrate the reliability of the tabulated values for the atomic form factor and the Compton-scattering correction. A brief discussion is included of the relative merits of x-ray vs neutron diffraction for obtaining the static structure factor.