Structure of zirconium tetrahydroborate Zr(BH4)4: A molecular dynamics study

Resumo

In the work the structural and thermodynamic characteristics of zirconium tetrahydroborate Zr(BH₄)₄ are considered. The initial compound organized in a cubic lattice was heated from absolute zero to temperatures exceeding the experimental boiling temperature. Temperature dependences of the parameters of the internal structure, energy, and density of molecules in bulk are obtained. It is found that on heating the compound to 300 K its structure is maintained and on further cooling it returns to the initial state. On heating above 400 K the irreversible destruction of the crystal lattice is observed. On further cooling the compound in the solid phase becomes amorphous. It is shown that in the new state the average binding energy is lower than that in the initial one and the cubic lattice has the highest binding energy among the considered Zr(BH₄)₄ structures.