Electron density distribution and crystal structure of lithium strontium silicate, Li2SrSiO4

Abstract

Crystal structure of Li2SrSiO4was reinvestigated by laboratory X-ray powder diffraction. The title compound was trigonal with space groupP3121,Z=3, unit-cell dimensionsa=0.502 281 (4) nm andc=1.245 520(8) nm, andV=0.272 129(3) nm3. The initial structural model was derived by the direct methods and further refined by the Rietveld method. The maximum-entropy method-based pattern fitting (MPF) method was used to confirm the validity of the structural model, in which conventional structure bias caused by assuming intensity partitioning was minimized. The final reliability indices calculated from MPF wereRwp=8.04%,S=1.22,Rp=6.01%,RB=1.50%, andRF=0.66%. Atomic arrangements of the final structural model were in excellent agreement with the three-dimensional electron-density distributions determined by MPF.