Computational Study for Amino Acid Production from Carboxylic Acid via C-14 beta-decay

To understand the chemical origin of life, we studied the probability of amino acid production via beta-decay from radiocarbon (C-14)-containing carboxylic acid. We developed a numerical simulation code that uses a Monte Carlo method for calculating the initial condition (recoil momentum of N-14 in C-14 beta-decay) and subsequent dynamical trajectory. We evaluated the productivity of the simplest amino acid [glycine (glycinium)] via C-14 beta-decay in [3-C-14]propionic acid as the probability of daughter nuclide N-14 remaining in the compound using the developed simulation. As a result, the probability of glycinium production was determined to be approximately 81%, assuming the molecular structures of [3-C-14-propionic acid and glycinium with amino group bonding dissociation energy of 3.9 eV estimated using the density-functional theory (DFT) method. Furthermore, according to the calculations with various bonding dissociation potential parameters, a probability of glycinium production of approximately 32% was expected even with a loose amino group bonding dissociation energy of 2 eV.