volcalc - Calculate Volatility of Chemical Compounds

Calculate estimated relative volatility index values for organic compounds based on functional group contributions. Calculation uses the SIMPOL.1 method in Prankow and Asher (2008) <doi:10.5194/acp-8-2773-2008> or modified SIMPOL.1 method as in Meredith et al. (2023) <doi:10.5194/acp-8-2773-2008>.