Lattice match in density functional calculations: ice Ih vs. beta-AgI

Area of Science:

• Materials Science
• Physical Chemistry
• Crystallography

Background:

• Understanding ice nucleation is crucial for atmospheric science and materials research.
• The role of lattice matching between substrates and water ice is a key factor in nucleation processes.
• Beta-AgI is a common substrate studied for its potential to influence ice formation.

Purpose of the Study:

• To investigate the lattice parameters of ice Ih and beta-AgI using Density Functional Theory.
• To quantify the lattice mismatch between ice Ih and beta-AgI using various Density Functional Theory functionals.
• To assess the suitability of Density Functional Theory for studying the significance of lattice match in ice nucleation.

Main Methods:

• Density Functional Theory optimizations were performed on crystal parameters of ice Ih and beta-AgI.
• A survey of eight common, approximate (non-hybrid) Density Functional Theory functionals was conducted.
• Lattice mismatches were calculated based on the optimized crystal parameters.

Main Results:

• Calculated lattice mismatches between ice Ih and beta-AgI ranged from 4.2% to 7.9%.
• The investigated Density Functional Theory functionals yielded significant lattice mismatches.
• These mismatches were found to be too large for a meaningful contribution to the discussion of lattice match significance.

Conclusions:

• Approximate Density Functional Theory functionals are not suitable for accurately predicting the lattice match between ice Ih and beta-AgI.
• The large calculated lattice mismatches suggest limitations in using these methods to study substrate-induced ice nucleation.
• Further methodological development or different theoretical approaches may be needed to address the role of lattice matching in ice nucleation.