A quantum-chemical study of synthesis and stability of glycine on olivine surface

CONTEXT: Using glycine as a model system, this study examines the surface assisted reaction between methylamine and formic acid on an olivine (010) surface. A comparative analysis of co-adsorbed, mixed phase, and gas phase pathways of methyl amine and formic acid to form glycine shows that a surface assisted pathway exists that connects adsorbed formic acid and methylamine to a surface stabilized glycine configuration with significantly reduced reaction energetics relative to gas phase, suggesting a plausible role for silicate minerals in facilitating complex organic synthesis under astro-physically relevant conditions. METHODS: First-principles density functional theory calculations were performed using the Vienna Ab initio Simulation Package (VASP) with the Perdew-Burke-Ernzerhof (PBE) exchange correlation functional and the projector augmented wave (PAW) method. Minimum energy reaction pathways and activation barriers were determined using the nudged elastic band (NEB) method, with all energies referenced to clearly defined initial states. Short time thermal stability of surface-bound glycine was assessed using ab initio molecular dynamics (AIMD) simulations at 1200 K to probe high temperature persistence on picosecond timescales.