Modeling Molecules for Field-Coupled Nanocomputing Circuit Design

Molecular Field-Coupled Nanocomputing (molFCN) is a highly low-power technology promising for digital electronics. It encodes information in the charge distribution of molecules and propagates it through electrostatic intermolecular interaction. Despite its potential, the molFCN technology suffers the absence of a functional design and simulation methodology. This paper provides a complete explanation of the characterization and modeling of molecules, from the molecular ab initio analysis to the design of molecular circuits and systems. Considering the diallyl-butane, we show how to use the ORCA package to derive, with DFT, the molecule geometry and charge distribution by correctly setting DFT functionals and basis sets. We study the molecule polarization when subjected to electric fields and enable the investigation of the interaction by exploiting the SCERPA tool. We set up the SCERPA simulation engine to simulate molecular circuits such as diallyl-butane wires. Finally, we show how to use literature results to model more complex molecules. We implement the bis-ferrocene cation in SCERPA and use it to create complex clocked logical devices. We simulate, as a means of explanation, a 0.0004 µm2 NAND gate.