Testing the atomic orbital graph as a basis for QSPR modeling of the boiling points of haloalkanes

1999 ◽  
Vol 40 (6) ◽  
pp. 950-958 ◽  
Author(s):  
A. A. Toropov ◽  
A. P. Toropova ◽  
N. L. Voropaeva ◽  
I. N. Ruban ◽  
S. Sh. Rashidova
Keyword(s):  
Atomic Orbital ◽  
Boiling Points ◽  
Qspr Modeling ◽  
Orbital Graph

Using the maximal topological distance matrix for QSPR modeling of the boiling points of cyclic hydrocarbons

1999 ◽  
Vol 40 (1) ◽  
pp. 169-172 ◽  
Author(s):  
A. A. Toropov ◽  
A. P. Toropova ◽  
N. L. Voropaeva ◽  
I. N. Ruban ◽  
S. Sh. Rashidova
Keyword(s):  
Distance Matrix ◽  
Cyclic Hydrocarbons ◽  
Topological Distance ◽  
Boiling Points ◽  
Qspr Modeling

scholarly journals New structure-based models for the prediction of normal boiling point temperature of ternary azeotropes

2021 ◽  
pp. 35-35
Author(s):  
Zohreh Faramarzi ◽  
Fatemeh Abbasitabar ◽  
Jalali Jahromi ◽  
Maziar Noei
Keyword(s):  
Statistical Tests ◽  
Model Performance ◽  
Absolute Error ◽  
Qsar Model ◽  
Qspr Model ◽  
Boiling Points ◽  
Azeotropic Mixtures ◽  
Qspr Modeling ◽  
Mathematical Equations ◽  
The Individual

Recently, development of the QSPR models for mixtures has received much attention. The QSPR modeling of mixtures requires the use of appropriate mixture descriptors. In this study, 12 mathematical equations were considered to compute mixture descriptors from the individual components for the prediction of normal boiling points of 78 ternary azeotropic mixtures. Multiple linear regression (MLR) was employed to build all QSPR models. Memorized_ACO algorithm was employed for subset variable selection. An ensemble model was also constructed using averaging strategy to improve the predictability of the final QSAR model. The models have been validated by a test set comprised of 24 ternary azeotropes and by different statistical tests. The resulted ensemble QSPR model had R2training, R2test, and q2 of 0.97, 0.95, and 0.96, respectively. Mean absolute error (MAE) as a good indicator of model performance were found to be 3.06 and 3.52 for training and testing sets, respectively.

Ab initio band theory approach to electron energy loss near edge structures

1988 ◽  
Vol 46 ◽  
pp. 506-507
Author(s):  
Xudong Weng ◽  
O.F. Sankey ◽  
Peter Rez
Keyword(s):  
Ab Initio ◽  
Local Density ◽  
Interpolation Method ◽  
Atomic Orbital ◽  
Plane Waves ◽  
Large Set ◽  
Theory Approach ◽  
Band Theory ◽  
Atomic Orbitals ◽  
Pseudopotential Calculations

Single electron band structure techniques have been applied successfully to the interpretation of the near edge structures of metals and other materials. Among various band theories, the linear combination of atomic orbital (LCAO) method is especially simple and interpretable. The commonly used empirical LCAO method is mainly an interpolation method, where the energies and wave functions of atomic orbitals are adjusted in order to fit experimental or more accurately determined electron states. To achieve better accuracy, the size of calculation has to be expanded, for example, to include excited states and more-distant-neighboring atoms. This tends to sacrifice the simplicity and interpretability of the method.In this paper. we adopt an ab initio scheme which incorporates the conceptual advantage of the LCAO method with the accuracy of ab initio pseudopotential calculations. The so called pscudo-atomic-orbitals (PAO's), computed from a free atom within the local-density approximation and the pseudopotential approximation, are used as the basis of expansion, replacing the usually very large set of plane waves in the conventional pseudopotential method. These PAO's however, do not consist of a rigorously complete set of orthonormal states.

Gas-Cycle-Assisted Headspace Solid-Phase Microextraction Coupling with Gas Chromatography for Rapid Analysis of Organic Pollutants

2021 ◽  
Author(s):  
Wenli Zhu ◽  
Peige Qin ◽  
Lizhen Han ◽  
Xiaowan Zhang ◽  
Dan Li ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Organic Pollutants ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Rapid Analysis ◽  
Headspace Solid Phase Microextraction ◽  
Boiling Points

Herein, a new gas-cycle-assisted (GCA) headspace solid-phase microextraction (HS-SPME) device was designed to rapidly extract organic pollutants with high Kow and boiling points that have difficulty in volatilization from matrix...

Polymer informatics: Expert-in-the-loop in QSPR modeling of refractive index

2021 ◽  
Vol 194 ◽  
pp. 110460
Author(s):  
Santiago A. Schustik ◽  
Fiorella Cravero ◽  
Ignacio Ponzoni ◽  
Mónica F. Díaz
Keyword(s):  
Refractive Index ◽  
Qspr Modeling
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