Abstract
The structure of the amorphous aluminoborane compound AlB4H11 was identified through a
collaborative study closely coupling a first-principles density functional based approach with
experimental measurements using IR, NMR, and neutron vibrational spectroscopy (NVS). The
AlB4H11 structure was found to contain distinct [BH4] and [B3H7] units without any [AlH4] units. It
forms a –[B3H7]–Al(BH4)– polymer chain with the [BH4] units twisted relative to each other
perpendicular to the chain direction and bonded to Al, and a chain backbone consists of [B3H7] and Al
where the [B3H7] unit exhibits a triangular boron configuration. The computed lowest energy structure
shows good agreement with results of IR, NVS and NMR spectra; this agreement demonstrates the
extended applicability of the structure prediction approach to the prediction of even amorphous
compounds.