Unveiling Hidden Shake-Up Features in the Uranyl M 4 -Edge Spectrum

TheM4,5-edgehighenergyresolutionX-rayabsorptionnear-edgestructure(HR-XANES)spectraof actinylsoffervaluableinsightsintothe electronicstructureandbondingpropertiesof heavy-elementcomplexes.Toconductacomprehensivespectralanalysis,it is essentialto employcomputationalmethodsthataccuratelyaccountfor relativisticeffectsandelectroncorrelation.In thiswork,weutilizevariationalrelativisticmultireferenceconfigurationalinteractionmethodstocomputeandanalyzethe X-rayM4-edgeabsorptionspectrumof uranyl.By employingtheseadvancedcomputationaltechniques,we achieveexcellentagreementbetweenthecalculatedspectralfeaturesandexperimentalobservations.Moreover,the calculationsunveilsignificantshake-upfeatures,whicharisefromthe intricateinterplaybetweenstronglycorrelated3d core-electronandligandexcitations.Thisresearchprovidesimportanttheoreticalinsightsintothespectralcharacteristicsof heavy-elementcomplexes.Furthermore,it establishesthefoundationforutilizingM4,5-edgespectroscopyas a meansto investigatethechemicalactivitiesof suchcomplexes.By leveragingthistechnique,we cangainadeeperunderstandingof the bondingbehaviorandreactivityof heavy-elementcompounds.