In this study, we investigate clusters of PA and its structurally similar analogs, lactic acid (LA), propionic acid (ProA), and 2,2-dihydroxypropionic acid (diol), by probing the geometries, computing cluster binding free energies, hydrate distributions, and IR absorption spectra. We specifically look at the intermolecular interactions between the organic acids, water and ions (Na + , Cl -and a NaCl pair). By viewing such clusters as a representation of the local aerosol surface environment, our aim is to elucidate how such small organic acids interact with the surface and enters the particle. Initial configurational sampling was performed with ABCluster program version 2.0, using a CHARMM force field. Subsequent single-point energies, geometries, and configurational sampling were calculated employing the GFN1-xTB method in the xtb software versions 6.4.0 and 6.4.1. Gaussian 16 version B.01 was utilized for the DFT geometry optimizations and vibrational frequency calculations at the ωB97X-D/6-31++G(d,p) level of theory. ORCA version 5.0.4 was employed for calculating high level single-point energies using the DLPNO-CCSD(T 0 )/aug-cc-pVTZ level. The DLPNO-CCSD(T 0 )/aug-cc-pVTZ//ωB97X-D/6-31++G(d,p) level of theory has been used extensively in the literature for studying the binding energetics of atmospheric molecular clusters and the choice is corroborated by additional benchmarking of the PA structures and interaction energies, carried out in this work (see Supporting Information). The above software was used as third-party programs implemented in the JKCS program, which fully automate the cluster configurational sampling.