Investigating vaterite phase stabilisation by a tetrazole molecule during calcium carbonate crystallization Massimiliano Massi*, Mark I. Ogden*, Franca Jones*† † corresponding author. E-mail: F.Jones@curtin.edu.au *Curtin University, Department of Chemistry, GPO Box U1987 6845 Perth Western Australia. Fax: 618 9266 4699; Tel: 618 9266 7677 Abstract Tetrazole compounds have recently been found to impact on crystal morphology but in a manner different to carboxylate molecules. One such molecule was found to stabilize vaterite and this was investigated by assessing the impact of systematic changes on its structure. It was found that both the tetrazole and the acetyl functionality were required for vaterite stabilisation. The mechanism of stabilisation appears to be via inhibition of vaterite dissolution. Keywords: A1. Biocrystallization, A1. Characterization, A1 Impurities, A1. Adsorption, A2. Growth from solutions, B1. Calcium compounds Introduction The impact of impurities or additives on crystal growth is relevant to many areas, including the control of scale formation, biomineralisation, pharmaceutical manufacturing, and so on [1-3]. From a fundamental perspective, additives have enabled the study of novel phenomena such as mesocrystal formation, by stabilising metastable crystalline structures [4, 5]. In biomineralisation, minerals-associated proteins are proposed to be a key component of the exquisite control of crystal