TANGO: A high through-put conformation generation and semiempirical method-based optimization tool for ligand molecules

2018 ◽  
Vol 40 (7) ◽  
pp. 900-909
Author(s):  
Vivek Gavane ◽  
Shruti Koulgi ◽  
Vinod Jani ◽  
Mallikarjunachari V. N. Uppuladinne ◽  
Uddhavesh Sonavane ◽  
...  
Keyword(s):  
Semiempirical Method ◽  
Conformation Generation

Influence of solvent polarity on the dual fluorescence of p-N,N-dimethylaminobenzonitrile: An AM1 theoretical study

1990 ◽  
Vol 55 (8) ◽  
pp. 1891-1895 ◽  
Author(s):  
Peter Ertl
Keyword(s):  
Excited State ◽  
Theoretical Study ◽  
Solvent Polarity ◽  
Semiempirical Method ◽  
Dual Fluorescence ◽  
Long Wavelength ◽  
Polar Media ◽  
Wavelength Emission ◽  
Ground State Geometry ◽  
Influence Of Solvent

Twisting of the NMe2 group in p-N,N-dimethylaminobenzonitrile (DMABN) was investigated using AM1 semiempirical method with configuration interaction. Effect of polar media was considered by placing + and - charge centers ("sparkles") at appropriate places opposite the molecule. Optimized ground state geometry of DMABN is slightly twisted with the lowest vertical excited state of 1B character. As the polarity of media increases and/or the - NMe2 group twists, the symmetric 1A excited state having considerable charge separation becomes energetically favorable. Anomalous long-wavelength emission of DMABN comes from this state.

A semiempirical method based on geminal functions

1968 ◽  
Vol 12 (3) ◽  
pp. 229-242 ◽  
Author(s):  
A. Ciampi ◽  
L. Paoloni
Keyword(s):  
Semiempirical Method

A Method for Correlating the Characteristics of Centrifugal Pumps in Two-Phase Flow

1978 ◽  
Vol 100 (4) ◽  
pp. 395-409 ◽  
Author(s):  
Jaroslaw Mikielewicz ◽  
David Gordon Wilson ◽  
Tak-Chee Chan ◽  
Albert L. Goldfinch
Keyword(s):  
Centrifugal Pump ◽  
Two Phase Flow ◽  
Flow Direction ◽  
Semiempirical Method ◽  
Head Loss ◽  
Phase Flow ◽  
Loss Ratio ◽  
Centrifugal Pumps ◽  
Reversed Flow ◽  
Two Phase

The semiempirical method described combines the ideal performance of a centrifugal pump with experimental data for single and two-phase flow to produce a so-called “head-loss ratio,” which is the apparent loss of head in two-phase flow divided by the loss of head in single-phase flow. This head-loss ratio is shown to be primarily a function of void fraction. It is demonstrated that the measured characteristics of a centrifugal pump operating in two-phase flow in normal rotation and normal and reversed flow directions (first and second -quadrant operation) and in reversed rotation and reversed flow direction (third-quadrant operation) can be reproduced with acceptable accuracy.

Web-Mediated Problem-Based Learning and Computer Programming: Effects of Study Approach on Academic Achievement and Attitude

2017 ◽  
Vol 56 (2) ◽  
pp. 272-292 ◽  
Author(s):  
Mustafa Yağcı
Keyword(s):  
Academic Achievement ◽  
Relevant Literature ◽  
Problem Based Learning ◽  
Semiempirical Method ◽  
Thinking Skills ◽  
Thinking Styles ◽  
Complex Nature ◽  
Study Approach ◽  
Students Attitudes ◽  
High Level

In the relevant literature, it is often debated whether learning programming requires high-level thinking skills, the lack of which consequently results in the failure of students in programming. The complex nature of programming and individual differences, including study approaches, thinking styles, and the focus of supervision, all have an effect on students’ achievement in programming. How students learn programming and the relationships between their study approaches and their achievement in programming have not yet been adequately illuminated. In this regard, the present study aims to investigate the effect of the study approach used on students’ attitudes toward programming and on their academic achievement within an online problem-based learning environment. In this study, a single-factor, pretest posttest single group and semiempirical method was utilized. The study was conducted on 41 students from a public university in Turkey. To implement problem-based learning activities, a teaching environment was created with the Moodle platform, allowing for group work and discussions. Seven status of the problems were prepared exclusively for the 12-week application period so that students could make suggestions about how to solve them. In the data collection phase, the Study Approach Scale, the Attitude Towards Programming Scale, and the Academic Achievement Test were employed. T-test and covariance analyses were carried out in the statistical analysis phase. According to the findings of the present study, students adopting the “deep” study approach were more successful than the students adopting a “superficial” approach. Moreover, it was determined that the problem-based learning application had a positive effect on students’ attitudes toward programming and that the study approach did not significantly affect the students’ attitude toward programming.

Semiempirical method of calculating isotopic composition of uranium and plutonium in irradiated fuel from a water-cooled-water-moderated reactor

1980 ◽  
Vol 48 (5) ◽  
pp. 294-296 ◽  
Author(s):  
B. A. Bibichev ◽  
A. V. Lovtsyus ◽  
V. P. Maiorov ◽  
M. A. Razuraeva ◽  
A. V. Stepanov ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Semiempirical Method ◽  
Irradiated Fuel

scholarly journals Assessing Conformer Energies using Electronic Structure and Machine Learning Methods

2020 ◽  
Author(s):  
Dakota Folmsbee ◽  
Geoffrey Hutchison
Keyword(s):  
Machine Learning ◽  
Electronic Structure ◽  
Density Functional ◽  
Large Scale ◽  
Single Point ◽  
Semiempirical Method ◽  
Coupled Cluster ◽  
Scale Evaluation ◽  
Machine Learning Methods ◽  
Electronic Structure Methods

We have performed a large-scale evaluation of current computational methods, including conventional small-molecule force fields, semiempirical, density functional, ab initio electronic structure methods, and current machine learning (ML) techniques to evaluate relative single-point energies. Using up to 10 local minima geometries across ~700 molecules, each optimized by B3LYP-D3BJ with single-point DLPNO-CCSD(T) triple-zeta energies, we consider over 6,500 single points to compare the correlation between different methods for both relative energies and ordered rankings of minima. We find promise from current ML methods and recommend methods at each tier of the accuracy-time tradeoff, particularly the recent GFN2 semiempirical method, the B97-3c density functional approximation, and RI-MP2 for accurate conformer energies. The ANI family of ML methods shows promise, particularly the ANI-1ccx variant trained in part on coupled-cluster energies. Multiple methods suggest continued improvements should be expected in both performance and accuracy.

scholarly journals Assessing Conformer Energies using Electronic Structure and Machine Learning Methods

2020 ◽  
Author(s):  
Dakota Folmsbee ◽  
Geoffrey Hutchison
Keyword(s):  
Machine Learning ◽  
Electronic Structure ◽  
Density Functional ◽  
Large Scale ◽  
Single Point ◽  
Semiempirical Method ◽  
Coupled Cluster ◽  
Scale Evaluation ◽  
Machine Learning Methods ◽  
Electronic Structure Methods

We have performed a large-scale evaluation of current computational methods, including conventional small-molecule force fields, semiempirical, density functional, ab initio electronic structure methods, and current machine learning (ML) techniques to evaluate relative single-point energies. Using up to 10 local minima geometries across ~700 molecules, each optimized by B3LYP-D3BJ with single-point DLPNO-CCSD(T) triple-zeta energies, we consider over 6,500 single points to compare the correlation between different methods for both relative energies and ordered rankings of minima. We find promise from current ML methods and recommend methods at each tier of the accuracy-time tradeoff, particularly the recent GFN2 semiempirical method, the B97-3c density functional approximation, and RI-MP2 for accurate conformer energies. The ANI family of ML methods shows promise, particularly the ANI-1ccx variant trained in part on coupled-cluster energies. Multiple methods suggest continued improvements should be expected in both performance and accuracy.

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