Explicitly correlated electrons in molecules

C Hattig, W Klopper, A Kohn, DP Tew - Chemical reviews, 2012 - ACS Publications
One of the central challenges of computational molecular investigation is the solution of the
time-independent, nonrelativistic BornÀ Oppenheimer electronic Schrödinger equation. For …

Theory and application of explicitly correlated Gaussians

J Mitroy, S Bubin, W Horiuchi, Y Suzuki… - Reviews of modern …, 2013 - APS
The variational method complemented with the use of explicitly correlated Gaussian basis
functions is one of the most powerful approaches currently used for calculating the …

Born–Oppenheimer and non-Born–Oppenheimer, atomic and molecular calculations with explicitly correlated Gaussians

S Bubin, M Pavanello, WC Tung, KL Sharkey… - Chemical …, 2013 - ACS Publications
Since the early work of Hylleraas on the helium atom, 1 it has been common knowledge that,
to accurately account for the interaction between the electrons in an atom or a molecule …

Pre-Born–Oppenheimer molecular structure theory

E Mátyus - Molecular Physics, 2019 - Taylor & Francis
ABSTRACT In pre-Born–Oppenheimer (pre-BO) theory a molecule is considered as a
quantum system as a whole, including the electrons and the atomic nuclei on the same …

Gaussians for Electronic and Rovibrational Quantum Dynamics

AP Woźniak, L Adamowicz, TB Pedersen… - The Journal of …, 2024 - ACS Publications
The assumptions underpinning the adiabatic Born–Oppenheimer (BO) approximation are
broken for molecules interacting with attosecond laser pulses, which generate complicated …

Rydberg spectrum of the boron atom

I Hornyák, S Nasiri, S Bubin, L Adamowicz - Physical Review A, 2021 - APS
Benchmark variational calculations of the lowest ten Rydberg S 2 states of two stable
isotopes of the boron atom (B 10 and B 11) are reported. The nonrelativistic wave functions …

Cold ion chemistry

D Zhang, S Willitsch - 2017 - books.rsc.org
Studying chemical reactions at very low temperatures is of importance for the understanding
of fundamental physical and chemical processes. At very low energies, collisions are …

Absolute frequency measurement of the transitions in neutral

KJ Ahrendsen, C Maruko, KR Albert-Aranovich… - Physical Review A, 2023 - APS
We report absolute frequency measurements on the three excited-state transitions
connecting the 2 p 2 (3 P) 3 s 2 P 1/2, 3/2 and 2 p 2 (3 P) 3 p 2 D 3/2, 5/2∘ states in neutral N …

Three-and four-electron integrals involving gaussian geminals: Fundamental integrals, upper bounds, and recurrence relations

GMJ Barca, PF Loos - The Journal of chemical physics, 2017 - pubs.aip.org
We report the three main ingredients to calculate three-and four-electron integrals over
Gaussian basis functions involving Gaussian geminal operators: fundamental integrals …

Beyond the Born-Oppenheimer approximation with quantum Monte Carlo methods

NM Tubman, I Kylänpää, S Hammes-Schiffer… - Physical Review A, 2014 - APS
In this work we develop tools that enable the study of nonadiabatic effects with variational
and diffusion Monte Carlo methods. We introduce a highly accurate wave-function ansatz for …