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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Singlet oxygen (O2) comes in two flavors -- namely the dominant lower-energya 1 Delta g state and the higher-energy shorter-lived b 1 Sigma + g state --and plays a key role in many photochemical and photobiological reactions. Forthis reason, and because of the large size of the systems treated, many papershave appeared with density-functional theory (DFT) treatments of the reactionsof 1 O 2 with different chemical species. The present work serves as a reminderthat the common assumption that it is enough to fix the spin multipicity asunity is not enough to insure a correct treatment of singlet oxygen. We reviewthe correct group theoretical treatment of the three lowest energy electronicstates of O 2 which, in the case of 1 O 2 is often so badly explained in therelevant photochemical literature that the explanation borders on beingincorrect and prevents, rather than encourages, a correct treatment of thisinteresting and important photochemical species. We then show how manyelectronic structure programs, such as a freely downloadable andpersonal-computer compatible Linux version of deMon2k, may be used, togetherwith the multiplet sum method (MSM), to obtain a more accurate estimation ofthe potential energy curves (PECs) of the two 1 O 2 states. Various strengthsand weaknesses of different DFAs emerge through our application of the MSMmethod. In particular, the quality of the a 1 Delta g excitation energyreflects how well functionals are able to describe the spin-flip energy in DFTwhile the quality of the b 1 Sigma + g excitation energy reflects how wellfunctionals are able to describe the spin-pairing energy in DFT. Finally wenote that improvements in DFT-based excited-state methods will be needed todescribe the full PECs of 1 O 2 including both the equilibrium bond lengths anddissociation behavior.

Practical Treatment of Singlet Oxygen with Density-Functional Theory and the Multiplet-Sum Method