English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The diagonal nonadiabatic term arising from the Born--Oppenheimerwave-function ansatz contains contributions from a vector and scalar potential.The former is provably zero when the wave function can be taken to be realvalued, and the latter, known as the diagonal Born--Oppenheimer correction(DBOC), is typically small in magnitude. Therefore, unless high accuracy issought, the diagonal nonadiabatic term is usually neglected when calculatingmolecular properties. In the presence of a magnetic field, the wave function isgenerally complex, and the geometric vector potential gives rise to a screeningforce that is qualitatively important for molecular dynamics. This screeningforce is written in terms of the Berry curvature and is added to the bareLorentz force acting on the nuclei in the presence of the field. In this work,we derive analytic expressions for the Berry curvature and DBOC using bothfirst and second quantization formalisms for the case of generalized andrestricted Hartree--Fock theories in a uniform magnetic field. The Berrycurvature and DBOC are calculated as a function of the magnetic field strengthand the bond distance for the ground-state singlets of H$_2$, LiH, BH, andCH$^+$. We also examine the stability and time-reversal symmetry of theunderlying self-consistent field solutions. The character of the DBOC and Berrycurvature is found to depend upon the magnetic field and varies betweenmolecules. We also identify instances of broken time-reversal symmetry for thedissociation curves of BH and CH$^+$.

Analytic Calculation of the Berry Curvature and Diagonal Born-Oppenheimer Correction for Molecular Systems in Uniform Magnetic Fields