Multi-scale global optimization of all-atom molecular models of n-alkanes

All-atom potential energy models of solid n-alkanes are important in understanding wax formation. Numerical results for molecular conformation computations using the multi-scale terrain/funneling method of Lucia and co-workers [Lucia, A., DiMaggio, P. A., & Depa, P. (2004a). A geometric terrain methodology for global optimization. Journal of Global Optimization, 29, 297; Lucia, A., DiMaggio, P. A., & Depa, P. (2004b). Funneling algorithms for multi-scale optimization on rugged terrains. Industrial & Engineering Chemistry Research, 43, 3770; Gattupalli, R. R., & Lucia, A. (2007). Molecular conformation of n-alkanes using terrain/funneling methods. Journal of Global Optimization, doi:10.1007/s10898-0079206-5] are reported for all-atom potential energymodels of the solid n-alkanes: dodecane, hexadecane, tetracosane, and triacontane, and comparedwith the basin hoppingmethod ofWales andDoye [Wales, D. J., &Doye, J. P. K. (1997).Global optimizationbybasinhoppingand the lowest energy structuresof LennardJones clusters containing up to 110 atoms. Journal of Physical Chemistry A, 101, 5111]. It is shown that the terrain/funneling method is capable of finding the global minimum energy molecular conformation for all examples in a reliable and efficient manner while basin hopping often fails. These numerical results provide strong evidencedemonstrating that themulti-scale terrain/funnelingmethod is a powerful global solvin