Generalized-gradient functionals in adaptive curvilinear coordinates

The incorporation of generalized-gradient exchange-correlation functionals within the adaptive curvilinear coordinate method for electronic structure calculations is discussed. It is demonstrated that a revised formulation of the exchange-correlation potential yields greatly improved convergence. Modifications of the forces on the adaptive coordinates compared to the local density case are derived. A strategy for incorporating gradient corrections at minimal computational cost compared to adaptive local-density calculations is outlined. {} 1996 The American Physical Society.