Theoretical investigations of candidate crystal structures for β-carbonic acid

Using multiple computational tools, we examine five candidate crystal structures for β-carbonic acid, a molecular crystal of environmental and astrophysical significance. These crystals comprise of hydrogen bonded molecules in either sheetlike or chainlike topologies. Gas phase quantum calculations, empirical force field based crystal structure search, and periodic density functional theory based calculations and finite temperature simulations of these crystals have been carried out. The infrared spectrum calculated from density functional theory based molecular dynamics simulations compares well with experimental data. Results suggest crystals with one-dimensional hydrogen bonding topologies (chainlike) to be more stable than those with two-dimensional (sheetlike) hydrogen bonding networks. We predict that these structures can be distinguished on the basis of their far infrared spectra.