Crystal structure of caesium di­hydrogen citrate from laboratory X-ray powder diffraction data and DFT comparison

The crystal structure of caesium di­hydrogen citrate, Cs+·H2C6H5O7−, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The coordination polyhedra of the nine-coordinate Cs+ cations share edges to form chains along the a-axis. These chains are linked by corners along the c-axis. The un-ionized carb­oxy­lic acid groups form two different types of hydrogen bonds; one forms a helical chain along the c-axis, and the other is discrete. The hy­droxy group participates in both intra- and inter­molecular hydrogen bonds.