A classical density-functional theory for describing water interfaces.

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Soft Matter Physics

Background:

• Accurate modeling of water's complex behavior is crucial in physical chemistry.
• Existing density functional theories often struggle to balance accuracy across different length scales and computational efficiency.

Purpose of the Study:

• To develop a novel classical density functional for water.
• To combine the strengths of White Bear fundamental-measure theory (FMT) and statistical associating fluid theory variable range (SAFT-VR).
• To achieve accurate predictions of water properties over wide temperature ranges and length scales.

Main Methods:

• Developed a hybrid density functional by integrating FMT for hard-sphere interactions with SAFT-VR for attractive forces.
• Applied the developed functional to model systems of hard rods and hard spheres in water.
• Evaluated the functional's performance across various temperatures and length scales.

Main Results:

• The new functional accurately reproduces water properties at both long and short length scales.
• The model demonstrates broad applicability across a wide range of temperatures.
• Computational efficiency is comparable to the original FMT, making it practical for simulations.

Conclusions:

• The developed classical density functional provides a computationally efficient and accurate method for simulating water.
• This hybrid approach effectively captures both hard-sphere and attractive interactions in water.
• The functional shows promise for applications in diverse systems involving water.