Conjugate vs direct nucleophilic addition on α,β-unsaturated carbonyl compounds

Computational simulations at Gaussian 09 to asses reactions between acrolein and organochalcogens.
Performing optimization and frequency calculations for energy change in conjugate and direct attack.
CH3O– is more reactive and produces more stable products by reacting with acrolein than CH3Se–.
Although oxygen is a “hard” nucleophile, it exhibits lower activation in conjugate addition.