Density Functional Study on Core Ionization Spectra of Cytidine and Its Fragments

摘要: The sugarIbase correlation of cytosine (base) and deoxyribose (sugar) moieties cytidine is investigated based on their inner-shell electronic structura li nformation. A recently developed density functional theory (DFT) model ,C VB3LYP, with a Gaussian-type basis set 6-311G**, the DFT-LB94 Slater-type TZ2P are employed to calculate inner shell ionization energies. results reveal that corresponding geometry not significantl yd ifferent from its fragments, i.e., deoxyribose. Changes in charge distribution respect concentrate local Cs ites base pyrimidine ring sugar ring, as indicated by atomi cH irshfeld charges. O-K, N-K, C-K spectra inherit aromati cs ignature cytosine, suggesting rol eo f cr ing i sab uffer diffuse changes brought addition moiety. Formation cytidine, however, substantially In general, correlated sites exhibit small red shifts base, whereas O-K show blue comparison those