Ab initio Description of Bond Breaking in Large Electric Fields

Area of Science:

• Surface chemistry
• Computational materials science
• Physical chemistry

Background:

• Strong electric fields (10^10 V/m) can break atomic bonds, offering potential for surface chemistry applications.
• Predicting the precise atomic-scale mechanisms of field-induced bond breaking remains challenging due to limitations in current theoretical tools.

Purpose of the Study:

• To develop a generalized dipole correction for charged repeated-slab models to accurately simulate strong electric fields.
• To enable direct theoretical treatment of electric field-induced bond-breaking events at the atomic scale.

Main Methods:

• Introduction of a generalized dipole correction for charged repeated-slab models.
• Theoretical treatment of electric field effects on surfaces.
• Simulation of field evaporation from a kinked tungsten (W) surface as a prototype application.

Main Results:

• The developed method allows for precise control of the electric field on both sides of the slab.
• Two distinct, qualitatively different desorption mechanisms were identified for field evaporation from a kinked W surface.
• The specific desorption mechanism is controllable by the magnitude of the applied electric field.

Conclusions:

• The generalized dipole correction provides a robust theoretical framework for studying field-induced bond breaking.
• This advancement opens new avenues for understanding and controlling surface chemistry under extreme electric fields.
• The findings offer insights into the selection of desorption mechanisms based on electric field strength.