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Mohammad Hossein Fatemi

Mohammad Hossein Fatemi

Academic rank: Professor
ORCID:
Education: PhD.
ScopusId:
Faculty: Faculty of Chemistry
Address: http://rms.umz.ac.ir/~mhfatemi/en/
Phone: 01135342931

Research

Title
In silico prediction of nematic transition temperature for liquid crystals using quantitative structure–property relationship approaches
Type
JournalPaper
Keywords
Nematic transition temperature · Quantitative structure–property relationship · Molecular descriptors · Artificial neural network · Liquid crystals
Year
2009
Journal Molecular Diversity
DOI
Researchers Mohammad Hossein Fatemi ، Mehdi Ghorbanzade

Abstract

Quantitative structure–propertyrelationshipmodels for the prediction of the nematic transition temperature (TN) were developed by using multilinear regression analysis and a feedforward artificial neural network (ANN). A collection of 42 thermotropic liquid crystals was chosen as the data set. The data set was divided into three sets: for training, and an internal and external test set. Training and internal test sets were used for ANN model development, and the external test set was used for evaluation of the predictive power of the model. In order to build the models, a set of six descriptors were selected by the best multilinear regression procedure of the CODESSA program. These descriptors were: atomic charge weighted partial negatively charged surface area, relative negative charged surface area, polarity parameter/square distance, minimum most negative atomic partial charge, molecular volume, and the A component of moment of inertia, which encode geometrical and electronic characteristics of molecules. These descriptors were used as inputs to ANN. The optimized ANN model had 6:6:1 topology. The standard errors in the calculation of TN for the training, internal, and external test sets using the ANN model were 1.012, 4.910, and 4.070, respectively. To further evaluate the ANN model, a crossvalidation test was performed, which produced the statistic Q2 = 0.9796 and standard deviation of 2.67 based on predicted residual sum of square. Also, the diversity test was performed to ensure the model’s stability and prove its predictive capability. The obtained results reveal the suitability of ANN for the prediction