P-A Colloquium: Relativistic and Quantum Electrodynamic Effects in Superheavy Elements

Speaker:  Peter Schwerdtfeger, Director of the Centre for Theoretical Chemistry and Physics, New Zealand Institute for Advanced Study at Massey University

Title:  Relativistic and Quantum Electrodynamic Effects in Superheavy Elements

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Refreshments at 3:30 pm in 1400 BPS.

Date: Thu, 26 Jan 2017, 4:10 pm - 5:10 pm  

Type: Colloquium

Location: 1415 BPS Bldg.

Abstract:
In the last decade we have seen the production of new elements for the Periodic Table up to nuclear charge 118. How far can we go? Where does the Periodic Table end? Can we do chemistry with such exotic elements? What is the chemical and physical behavior of these exotic elements, and do we have to go beyond nonrelativistic quantum mechanics to understand them? The current status of relativistic electronic structure theory for superheavy elements is reviewed.

[Fig.7 from Nucl.Phys.A 2015.02.005 article by Schwerdtfeger et al]

 

Recent developments in relativistic quantum theory have made it possible to obtain accurate electronic properties for the trans-actinide elements with the aim to predict their chemical and physical behavior. The role of quantum electrodynamic effects beyond the no-virtual-pair approximation, which is usually neglected in relativistic molecular calculations, is discussed. Changes in periodic trends due to relativistic effects are outlined for the superheavy elements with nuclear charge Z=111–120. We also analyze the role of the negative energy states for the electronic stability of superheavy elements beyond the critical nuclear charge (Zcrit≈170), where the 1s state enters the negative energy continuum at ?−2mec2.

Graph: Orbital energy dependence on nuclear charge Z. 1s1/2 shell diving into the negative energy continuum (−2mec2) at Zcrit.