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

Molecular electronic spectra can be represented in the time domain asauto-correlation functions of the initial vibrational wavepacket. We present aderivation of the harmonic vibrational auto-correlation function that is validfor both real and imaginary harmonic frequencies. The derivation rests on Liealgebra techniques that map otherwise complicated exponential operatorarithmetic to simpler matrix formulae. The expressions for the zero- andfinite-temperature harmonic auto-correlation functions have been carefullystructured both to be free of branch-cut discontinuities and to remainnumerically stable with finite-precision arithmetic. Simple extensions correctthe harmonic Franck-Condon approximation for the lowest-order anharmonic andHerzberg-Teller effects. Quantitative simulations are shown for severalexamples, including the electronic absorption spectra of F$_2$, HOCl, CH$_2$NH,and NO$_2$.

Franck-Condon spectra of unbound and imaginary-frequency vibrations via correlation functions: a branch-cut free, numerically stable derivation