Theoretical Calculations On The Polarizability And Correlation Parameters Of Atoms And Ions With Two Valance Electrons

The atomic dipole polarizabilities describe the changes in the charge distribution of an atom when it interacts with an electric field.As an elementary quantify,the polarizability is essential for the study of blackbody radiation shifts,quantum information,investigations of clusters structures and atomic clock.Therefore,the study of atomic structure parameters such as polarizability has always been a topic of great attention.For the multi-electron system,we do not get the accurate structure parameters by experimental methods,because of the complicated structure.So we need use the theoretical method to calculate the structure parameters.Therefore,in this work the configuration interaction with core polarization is used to calculate the structure parameter for the Be-like C²⁺,N³⁺and O⁴⁺ions and the Zn,Cd atoms Considering the core valence correlation,this method can deal well with the multi-body problems such as two valence electrons atomic ions.Zinc and cadmium atoms were found to have properties suitable for realizing the neutral atom optical lattice clock,so it is important to calculate the polarizability for zinc and cadmium.Meanwhile the ground state and excited states energy levels of Zn and Cd atoms are calculated,and the dipole polarizabilities are calculated and compared with the experimental and other theoretical values.We find that there are some disagreements in our calculation results,and the causes of errors are further analyzed.We also find that the influence of relativistic effect on its structure cannot be ignoredFor Be-like ions,the dipole polarizabilities of the ground state and the excited are crucial for performing the blackbody radiation shift and atomic clock.In this paper,the energy levels and the oscillator strengths of low-lying transitions of C²⁺,N³⁺and O⁴⁺are calculated,respectively.The static polarizabilities and tensor polarizabilities of C²⁺,N³⁺and O⁴⁺ions for the ground states 2s~2 ~1S^eand the excited states 2s2p ~3P^o and 2s2p ~1P^oare given.The ground state polarizability for C²⁺ion is 3.843a.u.,the present CICP calculation got the same result with CCSD(T)calculation.Present results of the dipole polarizabilities are consistent with the theoretical results within in accuracy of 1.6%.Compared with the other theoretical values,we find our values agreement with the other theoretical values and we also give the breakdown of the contributions to the dipole polarizabilities of the clock transition states.Finally we analyze the relationship between the dynamic polarizability and tune-out wavelength,and calculate the three longest tune-out wavelengths of C²⁺,N³⁺and O⁴⁺ions,respectively.It is found that the three tune-out wavelengths all occur close to the excitation energies for transition to ~1P^oor ~3P^o states.