We present a new computational approach based on Nuclear-Electronic Orbital and Subsystem Density Functional Theory. The resulting NEO-sDFT methodology enables quantum chemical calculations of large molecular systems composed of thousands of atoms while also describing selected protons quantum mechanically. A key feature of the associated program implementation is its flexibility in assigning quantum protons to subsystems, allowing different embedding schemes to be employed within a unified framework. The accuracy of NEO-sDFT is assessed by computing water dimer interaction energies, which exhibit errors of only a few meV compared to reference Nuclear-Electronic Orbital Density Functional Theory results. The favorable computational scaling of NEO-sDFT is further showcased through calculations on water clusters of increasing size, with up to 303 protons being treated quantum mechanically. Our results demonstrate that NEO-sDFT is an accurate and efficient approach for incorporating nuclear quantum effects into large-scale simulations, providing a foundation for future applications to proton transfer processes in biochemical systems.
Nuclear–electronic orbital (NEO) methods treat specified nuclei, typically protons, quantum mechanically on the same level as electrons within quantum chemical calculations. This approach allows the computationally efficient inclusion of nuclear quantum effects such as nuclear delocalization, anharmonic zero-point en...
Rowan J. Goudy, Sharon Hammes-Schiffer· Journal of Chemical Theory a...· 0 citations
Nuclear quantum effects play a critical role throughout chemistry, biology, and materials science. This Perspective presents the nuclear–electronic orbital (NEO) framework as a viable approach for incorporating nuclear quantum effects into calculations of relatively large, complex systems. The NEO approach treats spe...
Sharon Hammes-Schiffer· Journal of the American Chem...· 0 citations
Nuclear quantum effects are critical for describing proton transfer and hydrogen bonding, but their incorporation into quantum chemistry calculations is often computationally prohibitive on classical hardware. A promising alternative are quantum computers due to their linear scaling in the space requirements with syste...
Lukas Haßfurth, Juliane Heitkämper, Elias Walter et al.· 0 citations
This review presents a concise overview of the theoretical foundations of DFT and the major approximations used in modern calculations, as well as the practical workflow from structural preparation and convergence testing to geometry optimization, electronic-structure calculations and property analysis.
Hariharan Vaiyapuri Manemaran, Girija Kesavan· International Journal of Mul...· 0 citations
Orbital-free density functional theory seeks to compute the energy of an electronic system directly from its electron density, avoiding one-electron wave functions and thereby offering a route to scalable electronic structure calculations. Machine-learned orbital-free density functionals have recently achieved promisin...
Simon Wagner, Marc K. Ickler, Manuel V. Klockow et al.· 2 citations
First-principles calculations play a pivotal role in contemporary chemical studies. The most commonly employed algorithms are based on density functional theory (DFT), and in certain instances, the Hartree-Fock method is also utilized. Although these two methods can efficiently yield accurate results for small-to-mediu...
