Abstract:  https://technion.zoom.us/s/97510903992#success
Atomic physics is still at the frontier of our exploration of fundamental physical laws. For example, the comparison of the theoretical and experimental values of the atomic parity nonconservation (PNC) amplitude, which, as we will show, arises from GlashowWeinberg theory of electroweak interactions, constitutes one of the most stringent tests of the Standard Model. By reviewing current theoretical and experimental data, we will see, however, that the theoretical results lag behind the latter. Moreover, there are several calculations on the cesium atom, for example, that diﬀer at a subpercentage level. There are two main obstacles inherent in any precise atomic structure calculation: frst, the determination of an optimal radial basis and a numerically stable evaluation of atomic integrals, and second, the question of how to take into account electron correlation. We describe our solution of the former [1] and our current eﬀorts for solving the latter [2]. The optimal radial basis are the Sturmian functions. They are orthonormal, discrete and complete on infnite interval. The problem of the numerical stability is solved by considering Sturmian functions not “analytically”, i.e. through their explicit functional form, but “algebraically”, i.e. as functions satisfying certain recursion relations. These recursion relations then imply recursion relations for the integrals of these functions. The electron correlation in closedshell atoms can be accurately accounted for by the coupledcluster method. In the case of openshell atoms, one can use a combination of coupledcluster and confguration interaction methods. We describe the adaptation of these methods to the spherical symmetry of the atoms. [1] T. Uhlířová, J. Zamastil, and J. Benda, Comput. Phys. Commun. 280, 108490 (2022). [2] T. Uhlířová and J. Zamastil, in progress.
