Relativistic corrections to the electric field gradient given by linear response elimination of the small component (LRESC) formalism.

AUCAR, JUAN J.; MALDONADO, ALEJANDRO F.; MELO, JUAN I.

Asís

Congreso; 13º International Congress of Relativistic Effects on Heavy Elements; 2022

In this work we analyze relativistic effects on the electric field gradients (EFGs) via the linear response elimination of the small component scheme (LRESC) in order to give insight of the electronic origin of relativistic corrections. Within LRESC we obtain relativistic corrections to EFG in terms of 1/c (the speed of light) formally showing that, up to first order (1/c2 ), there are no virtual pair contributions, recovering the so-called “no-pair” approximation. Virtual pair contributions and triplet corrections arise at second order (1/c⁴ ) . Within the LRESC scheme it is possible to analyze the electronic mechanisms coming from the small and large components of the 4c wave function. We included all triplet corrections of 1/c⁴ order coming from both components.