# Density functional theory and oxygen spin

I would like to perform single-point/geometry-optimization/NEB calculations on systems involving both molecular oxygens and adsorbed oxygens. Reductions by hydrogens are also involved.

I am still struggling to find an approach to deal with the spin. Molecular oxygen is a triplet, but this is not the case after/during a reaction/adsorption.

The DFT calculation should be able to find a triplet electronic state for molecular oxygens (gas phase) without me enforcing it.

I am using Quantum ESPRESSO currently and I am still unsure about spin calculations in general.

I am pretty sure about using nspin=2 (spin-polarized calculation) and not setting any tot_magnetization. For a simple isolated molecular oxygen molecule the final magnetization is around 0.7 per atom, so should I put this value as "starting_magnetization" for the oxygen element?