(329a) Contact-Value Self-Consistency in Density Functional Theory Calculations

Density functional theory (DFT) calculations are typically based on an approximate functional that connects the properties of a multi-body system with the underlying one-body density distributions. The state of art for classical systems is to represent the functional in terms of the fundamental measure theory for the molecular excluded volume effects and the Gaussian perturbation for various components of the long-range intermolecular forces. Unlike the conventional local-density or mean-field approximations, the more sophisticated functional is able to reproduce simulation results quantitatively without the significant increase of the computational burden. Nevertheless, any approximation introduced in the functional formulation may violate the statistical-mechanical sum rules leading to thermodynamic inconsistency. In this work, we introduced a new computational procedure for the implementation of the DFT calculations that conform exact statistical-mechanical relations. The numerical performance of the new theoretical method has been demonstrated by its application to predicting the structure of electric double layers within the standard electrolyte models. Drastic improvement has been found in comparison of the DFT calculations with the simulation results.