Theoretical Study of the Dehydration Process of MgCl2 center dot 4H(2)O to MgCl2 center dot 2H(2)O

Density functional theory was employed to study the dehydration mechanism of MgCl2 center dot 4H(2)O. Analysis of potential energy surface (PES) of possible pathways indicated that the most possible way was one of the water molecules halfly dissociated with an elongated bond distance with Mg2+, where electrostatic interaction played a leading role; another water molecule dissociated sequentially. It was in agreement with the result from differencial thermal analysis. The dehydration process of MgCl2 center dot 4H(2)O was clarified theoretically, promoting the theoretical study of dehydration of MgCl2 center dot 2H(2)O.