A refinement of the crystal structure of Na2CO3 H2O

The crystal structure of synthetic Na2CO3·H2O has been refined using 1231 unique x-ray diffraction data collected by the peak height method on a diffractometer. R = 0.034. The unit cell is a = 6.474(2), b= 10.724(3) and c = 5.259(2) Å with z = 4 and space group P21ab. The calculated density is the same as the observed density, 2.26 g·cm-3. The structure contains sheets of CO32- ions bonded to Na+ ions and water molecules roughly halfway between the sheets. Each CO32- bonds edgewise to both Na+ ions. The Na+ ions have irregular but similar coordinations of seven neighbors. Each water molecule is bonded to both Na+ ions and forms hydrogen bonds to both neighboring CO32- layers.