1. Applications   Semiconductors   Electric & Magnetic Devices   Carbon Nanotubes   Oxide materials   Nanoparticles and Nanocrystals   Dielectrics Algorithms & Modeling   Schrodinger Equations   Density Functional Theory   Large Eigenvalue Problems   Atomic Force Microscopy Funding: DOE, NSF, Navy CCM Research Simulated atomic force microscopy image of the hexabenzocoronene molecule. Jim Chelikowsky Director Affiliated Faculty Alex Demkov Juan Sanchez Research Staff: Na Sai, Jaime Souto

2. Simulation of Non-Contact Atomic Force Microscopy - CCM The Atomic Force Microscope (AFM) was developed to overcome a basic drawback with scanning tunneling microscopy (STM) - that it can only image conducting or semiconducting surfaces. The AFM, has the advantage of imaging almost any type of surface, including polymers, ceramics, composites, glass, and biological samples. 2

3. Simulation of Non-Contact Atomic Force Microscopy - Simulation of Non-Contact Atomic Force Microscopy - CCM Simulated AFM image from first-principles Experiment Simulated AFM image using our method Theoretical Challenge: Determine the forces of the sample on the tip of the probe. The atomic structure of silver deposited on a silicon surface. Quantum mechanical methods are used to find the force of the substrate on the tip. This force perturbs the vibrational modes of the probe and knowing this force allows us to replicate the AFM image. Our methods are simple and can be used to rapidly screen structural models and most importantly requires knowledge of the substrate alone. Current work includes imaging nanostructures, and large biological molecules. Quantum mechanical methods are used to find the force of the substrate on the tip. This force perturbs the vibrational modes of the probe and knowing this force allows us to replicate the AFM image. Our methods are simple and can be used to rapidly screen structural models and most importantly requires knowledge of the substrate alone. Current work includes imaging nanostructures, and large biological molecules. 3