Exterior derivative of a one-form evaluated on vector fields

For a smooth one-form $\alpha$ and smooth vector fields $X,Y$,In coordinates the derivatives of the components of $X,Y$ cancel against the Lie bracket of vector fields, leaving $({\partial }_i{\alpha }_j-{\partial }_j{\alpha }_i)X^i{Y}^j$. This formula extends the coordinate definition of the exterior derivative to arbitrary frames.