Structure and stability of aluminium trihydroxides bayerite and gibbsite: A quantum mechanical ab initio study with the CRYSTAL06 code

The structure and energetics of bayerite and gibbsite have been investigated at the periodic ab-initioquantum-mechanical level by using a Gaussian type basis set and the B3LYP Hamiltonian.Both systems have layered structure, with intra-layer and inter-layer hydrogen bonds (HBs). In gibbsitethe latte...

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Bibliographic Details
Main Authors: Demichelis, Raffaella, Civalleri, B., Noel, Y., Meyer, A., Dovesi, R.
Format: Journal Article
Published: Elsevier 2008
Online Access:http://hdl.handle.net/20.500.11937/17423
Description
Summary:The structure and energetics of bayerite and gibbsite have been investigated at the periodic ab-initioquantum-mechanical level by using a Gaussian type basis set and the B3LYP Hamiltonian.Both systems have layered structure, with intra-layer and inter-layer hydrogen bonds (HBs). In gibbsitethe latter are stronger than in bayerite: 23.15 and 17.59 kJ/mol, respectively. The formation Gibbs freeenergy has been calculated, including entropic and enthalpic contributions: at 298 K gibbsite is more stable than bayerite by 7.74 kJ/mol.