Prediction of many-electron wavefunctions using atomic potentials: refinements and extensions to transition metals and large systems

TL;DR

This paper presents a method to predict many-electron wavefunctions using atomic potentials, with extensions for transition metals and large systems, achieving high accuracy in molecular energy predictions.

Contribution

It introduces transferable atomic potentials and refinement techniques for accurate wavefunction prediction in complex molecules and large systems.

Findings

Transferable potentials yield energies within 0.05 eV of exact methods.

Refinements improve accuracy for transition metals and large molecules.

Successful application to nanoparticle and chlorophyll-s states.

Abstract

For a given many-electron molecule, it is possible to define a corresponding one-electron Schr\"odinger equation, using potentials derived from simple atomic densities, whose solution predicts fairly accurate molecular orbitals for single- and multi-determinant wavefunctions for the molecule. The energy is not predicted and must be evaluated by calculating Coulomb and exchange interactions over the predicted orbitals. Transferable potentials for first-row atoms and transition metal oxides that can be used without modification in different molecules are reported. For improved accuracy, molecular wavefunctions can be refined by slightly scaling nuclear charges and by introducing potentials optimized for functional groups. For a test set of 20 molecules representing different bonding environments, the transferable potentials with scaling give wavefunctions with energies that deviate from exact self-consistent field or configuration interaction energies by less than 0.05 eV and 0.02 eV per bond or valence electron pair, respectively. Applications to the ground and excited states of a Ti18O36 nanoparticle and chlorophyll-s are reported.