The Chemistry Department, The Colorado College, Colorado
Springs, CO 80903
phone 719-389-6437, fax 719-389-6929
(c) R.E. Tuzun (d) Bobby G. Sumpter (d) Donald W. Noid
Chemical and Analytical Sciences Division, Oak Ridge
National Laboratory, Oak Ridge, TN 37831,
phone 615-574-4992, fax 615-576-5235,
The degree of positional stability of nanomechanical devices will be paramount in determining the way devices can be constructed, their performance and operational conditions or capability. Because of this we have used computational simulations to examine the positional stability of one-dimensional carbon rods (both harmonic and anharmonic models) as a function of length and temperature. Both molecular dynamics and Monte Carlo statistical mechanics were used to calculate the variance of the end of rods 10 to 1000 carbon atoms long. These results were compared to the variance calculated with the classical equation derived by Drexler that uses a harmonic approximation. The variance of the end atom in each rod seems large, but the question of what this will mean for building nanostructures is difficult to answer. Further study of the same systems are underway using Quantum Monte Carlo methods to obtain a wavefunction (both harmonic and anharmonic models) for the carbon rods. This wavefunction will then to used to determine the variance of the end of these carbon rod systems from 10 to 1000 atoms long. It is anticipated the quantum study will give very different results from the three classical methods. If the classically calculated variance is canceled in the quantum studies then the question of the significance of the variance will be easier to answer. The results of all the calculations using classical theories as well as the quantum calculation will be compared and presented in this poster.