Quanty for core level spectroscopy - excitons, resonances and band excitations in time and frequency domain

摘要

Dependingonthematerialandedgeunderconsideration,corelevelspectramanifestthemselvesaslocalexcitonswithmultiplets,edgesingularities,resonances,orthelocalprojecteddensityofstates.Bothextremes,i.e.,localexcitonsandnon-interactingdelocalizedexcitationsaretheoreticallywellundercontrol.Describingtheintermediateregime,wherelocalmanybodyinteractionsandband-formationareequallyimportantisachallenge.HerewediscusshowQuanty,aversatilequantummanybodyscriptlanguage,canbeusedtocalculateavarietyofdifferentcorelevelspectroscopytypesonsolidsandmolecules,bothinthefrequencyaswellasthetimedomain.TheflexiblenatureofQuantyallowsonetochoosedifferentapproximationsfordifferentedgesandmaterials.Forexample,usinganewlydevelopedmethodmergingideasfromdensityrenormalizationgroupandquantumchemistry[1-3],Quantycancalculateexcitons,resonancesandband-excitationsinx-rayabsorption,photoemission,x-rayemission,fluorescenceyield,non-resonantinelasticx-rayscattering,resonantinelasticx-rayscatteringandmanymorespectroscopytypes.Quantycanbeobtainedfrom:http://www.quanty.org...