Calculation of the stability of nonperiodic solids using classical force fields and the method of increments: N2O as an example

Authors: Carsten Müller and Daniel Spångberg

Combining classical force fields for the Hartree–Fock (HF) part and the method of increments for post-HF contributions, we calculate the cohesive energy of the ordered and randomly disordered nitrous oxide (N₂O) solid. At 0 K, ordered N₂O is most favorable with a cohesive energy of −27.7 kJ/mol. At temperatures above 60 K, more disordered structures become compatible and a phase transition to completely disordered N₂O is predicted. Comparison with experiment in literature suggests that experimentally prepared N₂O crystals are mainly disordered due to a prohibitively high activation energy of ordering processes.

J. Comput. Chem., 36, (2015), 1420–1427
DOI: 10.1002/jcc.23939