Partial atomic multipoles for internally consistent microelectrostatic calculations.

Area of Science:

• Computational Chemistry
• Materials Science
• Condensed Matter Physics

Background:

• Accurate calculation of electrostatic energies in molecular solids is crucial for understanding material properties.
• Existing microelectrostatic methods have limitations in handling complex systems like doped, defected, or disordered materials.

Purpose of the Study:

• To develop an advanced computational methodology for the self-consistent calculation of electrostatic energies in molecular solids.
• To extend microelectrostatic methods by incorporating distributed generalized polarizability derived from Coupled Perturbed Hartree-Fock (CPHF) equations.

Main Methods:

• Utilized Coupled Perturbed Hartree-Fock (CPHF) equations to derive a distributed generalized polarizability matrix.
• Implemented a self-consistent iterative approach to adjust molecular electronic distributions and local electric fields.
• Accounted for atomic partial multipoles up to order 2 for precise molecular charge density representation.

Main Results:

• Successfully calculated electrostatic energies for charge carrier and charge-transfer (CT) states in various molecular solids.
• Reproduced significant charge-quadrupole contributions to CT state energies in low-symmetry environments.
• Demonstrated the method's efficiency for large-scale calculations (up to 300,000 atoms).

Conclusions:

• The proposed method offers a precise and efficient way to compute electrostatic energies in complex molecular solids.
• The approach accurately captures charge distributions and electric field interactions, including higher-order multipole effects.
• This methodology holds potential for describing electrostatic solvent effects and advancing the study of molecular materials.