Multiconfiguration Density-Coherence Functional Theory

This paper presents a new theory called multiconfiguration density coherence functional theory (MC-DCFT). This theory provides a new route to define density functionals for multiconfiguration wave functions, in particular by using the one-particle density matrix in the coordinate representation. The theory is illustrated by calculating the dissociation curve of four heteronuclear and homonuclear diatomic molecules, namely, H-2, F-2, N-2, and HF, using density coherence functionals converted from PBE, BLYP, and PW91. By introducing two parameters in the converted density functionals, we are able to calculate bond dissociation energies of comparable accuracy as those calculated by multiconfiguration pair-density functional theory (MC-PDFT) and complete active space second-order perturbation theory (CASPT2). This demonstrates that it would be possible to build a successful multiconfiguration density functional theory based on density coherence.

Automated summary

The paper introduces a new theory named MC-DCFT, which provides a new route to define density functionals for multiconfiguration wave functions by using the one-particle density matrix in the coordinate representation. The theory is demonstrated by calculating dissociation curves of four diatomic molecules and achieving comparable accuracy with other calculation methods by introducing two parameters in converted density functionals.