Constrained nuclear-electronic orbital (CNEO) framework for accurate and efficient simulations of hydrogen bonded systems*

Nuclear quantum effects have a significant impact on the structure, spectra, and dynamics of many hydrogen bonded systems. Nevertheless, it remains highly challenging to accurately incorporate these effects into large-scale molecular simulations. Over the past five years, my group has developed the constrained nuclear-electronic orbital (CNEO) framework for accurate and efficient calculations and simulations for systems containing hydrogen atoms. When compared to the conventional Born-Oppenheimer framework, the CNEO framework directly describes the quantum delocalized nature of nuclei, resulting in significantly improved vibrational spectra and reaction dynamics for hydrogen bonded systems than conventional ab initio molecular dynamics. The CNEO framework represents a novel approach to describing nuclear quantum effects. Its high accuracy and efficiency hold great promise for addressing more complex chemical and biological systems with intricate hydrogen bonded structures.