An embedding scheme for constraint-based orbital-optimized excitations in molecular and bulk environments.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Theoretical Chemistry

Background:

• Accurate calculation of electronically excited states is crucial in chemistry.
• Existing methods like ΔSCF have limitations in evaluating arbitrary electronic excitations.
• The constraint-based orbital-optimized excited state (COOX) method offers advantages for excited state calculations.

Purpose of the Study:

• To introduce an embedding scheme for the COOX method.
• To enable accurate calculation of specific excited states within complex environments.
• To investigate the validity and applicability of the new embedding scheme.

Main Methods:

• Developed an embedding scheme for the COOX method.
• The constraint potential is derived from a sub-system calculation.
• Applied the method to exemplary calculations to assess its performance.

Main Results:

• The embedding scheme successfully enables the evaluation of specific excited states in complex systems.
• The approach overcomes limitations of conventional methods for such calculations.
• Initial exemplary calculations demonstrate the method's validity and applicability.

Conclusions:

• The presented embedding scheme extends the capabilities of the COOX method.
• This approach provides a powerful tool for studying excited states in intricate molecular environments.
• Further investigations will explore the full range of applicability of this novel embedding scheme.