Thermodynamic and optical properties of HCOOH(H 2 O) n and HCOOH(NH 3 )(H 2 O) ( n -1) clusters at various temperatures and pressures: a computational study.

Density functional theory has been used to compute the gas-phase geometries, binding energies, ZPE-corrected binding energies, BSSE-corrected binding energies, binding enthalpies, and binding free energies of HCOOH(H 2 O) n and HCOOH(NH 3 )(H 2 O) ( n -1) clusters with n = 1-8, 10, 12, 14, 16, 18, and 20. Enthalpies and free energies are calculated for a range of atmospherically relevant temperatures ( T ) and pressures ( P ) (from T = 298.15 K, P = 1013.25 hPa to T = 216.65 K, P = 226.32 hPa). The optical properties of those clusters have been studied at the CAM-B3LYP/aug-cc-pVDZ level of theory.