Efficient quantum mechanical calculation of solvation free energies based on density functional theory, numerical atomic orbitals and Poisson–Boltzmann equation

We have successfully coupled the Kohn–Sham with Poisson–Boltzmann equations to predict the solvation free energy, where the Kohn–Sham equations were solved by implementing the flexible pseudo atomic orbitals as in Siesta package. It was found that the calculated solvation free energy is in good agreement with experimental results for small neutral molecules, and its standard error is 1.33 kcal/mol, the correlation coefficient is 0.97. Due to its high efficiency and accuracy, the proposed model can be a promising tool for computing solvation free energies in computer aided drug design in future.