Capturing Multiconfigurational Effects in Nanoscale Charge Transport
Charge transport in nanoscale systems such as molecules has long been a topic of intense study due to the quantum character of their transport This leads to unique quantum transport phenomena in molecule sized devices that are not observed in traditional electronics For example, in a traditional electronic resistor, conductance is expected to decay as the device length increases For some molecular resistor series, it has been predicted that conductance can instead increase with molecular/device length, an idea that has been called reversed conductance decay or anti ohmic conductance While such reversals of conductance decay have been repeatedly theoretically predicted, they have been difficult to demonstrate experimentally. Previous studies have suggested that theoretical multi reference(static) correlation errors may be an important cause of this discrepancy, yet most single molecule transport methods are unable to treat multireference correlation To address this issue, we developed a new approach for the study of single molecule electronic systems, denoted NEGF MCPDFT, which combines multiconfiguration pair density functional theory (MC PDFT) with non equilibrium Green’s functions ( NEGF MCPDFT allows for the efficient inclusion of both static and dynamic electron correlations in the description of the electronic structure while still supporting a similar electrode description as traditional single reference NEGF DFT methods In this presentation, we outline the development of the NEGF MCPDFT methodology, discuss new strategies for improving NEGF MCPDFT’s treatment of electrode molecule interactions, and detail its application to conductance decay reversals.
Hosted by Professor Rick Remsing
~Coffee/tea will be served prior to the lecture~