Completed Optimised Structure of Threonine Molecule by Fuzzy Logic Modelling

Abstract

In this study we applied the fuzzy logic approach in order to model the energy depending on the two torsion angles for the threonine (C4H9NO3) molecule. The model is set up according to theoretical results obtained by the density functional theory (B3LYP) with a 6-31 G(d) basic set on a Gausian program. We aimed to determine the best torsion angle values providing the energy of the molecule minimum by a fuzzy logic approach and to compare them with the density functional theory results. It was concluded that the fuzzy logic approach gives information about the untested data and its best value which are expensive and time-consuming to obtain by other methods and experimentation.

A novel modeling and smoothing technique in global optimization

“…The global minimum point of the problem is found approximately as (186 • , 179 • ) with the corresponding energy value −438.268 Hartree/particle in [23]. In this study, the global minimum value is obtained exactly as (181.6167 • , 187.5836 • ) with the corresponding energy value −438.2678 Hartree/particle.…”

“…We compare our global optimization method with the methods in [16] and [5]. As a real-life application, we apply our new methodology to construct the model function of the energy structure problem in [23] and minimize this model function.…”

“…In this study, we first propose a new surface construction method and present a new global optimization method. As an application, we consider the data obtained from DFT calculations [23]. Second, we take a partition of the obtained data and we construct Bezier surface patches by using the data for each element of the partitions.…”

“…The data is obtained from DFT calculations of the Theronine molecule. In the calculations, the molecular structure was taken with two torsion (SC1 = C2C1C4O7 and SC2 = C1C2O6H13) angles and scanned around these [23]. We follow the Algorithm 2 for constructing the smooth model of the data points and for finding the global minimizer.…”