Exploring the Possibility of Noncovalently Surface Bound Molecular Quantum-Dot Cellular Automata: Theoretical Simulations of Deposition of Double-Cage Fluorinated Fullerenes on Ag(100) Surface

The double-cage fluorinated fullerene (C20F18(NH)(2)C20F18) has been suggested to be a new kind of molecular quantum-dot cellular automata (MQCA) candidate. The possibility of noncovalently binding these candidate molecules on silver substrates is explored by molecular dynamics (MD) simulations. It is demonstrated that the candidate molecules can deposit on Ag(100) surface and form ordered MQCA arrays in both head-to-tail and side-by-side styles. The side-by-side array can keep intact even at room temperature, while the head-to-tail array shows larger thermal fluctuations. In comparison with the Ag(100) surface, ordered arrays can only be observed in the side-by-side style at low temperatures on Ag(111) surface. Density functional theory (DFT) calculations of the charge redistribution of the candidate, in response to an electrostatic driver, show that the QCA function of the candidate still maintains with the introduction of the Ag surface. In addition, a simple (Coulomb) electrostatic model is proposed to simulate the dynamical signal transmission in our MQCA wire. The transmission time is affected by the wire length as well as the long-range intercellular electrostatic interactions.