DOES FULMINIC ACID HAVE A BENT EQUILIBRIUM STRUCTURE

Self-consistent (Kohn-Sham) density functional theory is used to study the structure of fulminic acid (HCNO). Using the local-density approximation functional (the Slater and Vosko-Wilk-Nusair approaches), HCNO is linear with a large basis set. However, using the improved functional of Becke and of Lee, Yang and Parr, HCNO remains bent for all basis sets, with the best predicting a barrier to linearity of 16 cm-1. All computed frequencies at the optimized geometry agree very well with observed frequencies. It is concluded that HCNO has a very slightly bent equilibrium structure.