scholarly journals Efficient Evaluation of Molecular Electrostatic Potential in Large Systems

Computation ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 64
Author(s):  
Rafael Lopez ◽  
Frank Martinez ◽  
Ignacio Ema ◽  
Jose Manuel Garcia de la Vega ◽  
Guillermo Ramirez
Keyword(s):  
Electron Density ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Computation Time ◽  
Basis Set ◽  
Efficient Computation ◽  
Multipole Moments ◽  
Atomic Orbitals ◽  
Electron Density Matrix ◽  
Large Systems

An algorithm for the efficient computation of molecular electrostatic potential is reported. It is based on the partition/expansion of density into (pseudo) atomic fragments with the method of Deformed Atoms in Molecules, which allows to compute the potential as a sum of atomic contributions. These contributions are expressed as a series of irregular spherical harmonics times effective multipole moments and inverse multipole moments, including short-range terms. The problem is split into two steps. The first one consists of the partition/expansion of density accompanied by the computation of multipole moments, and its cost depends on the size of the basis set used in the computation of electron density within the Linear Combination of Atomic Orbitals framework. The second one is the actual computation of the electrostatic potential from the quantities calculated in the first step, and its cost depends on the number of computation points. For a precision in the electrostatic potential of six decimal figures, the algorithm leads to a dramatic reduction of the computation time with respect to the calculation from electron density matrix and integrals involving basis set functions.

Basis set dependence of the molecular electrostatic potential topography. A case study of substituted benzenes

1995 ◽  
Vol 239 (4-6) ◽  
pp. 273-281 ◽  
Author(s):  
Shridhar R. Gadre ◽  
Sudhir A. Kulkarni ◽  
C.H. Suresh ◽  
Indira H. Shrivastava
Keyword(s):  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Basis Set ◽  
Substituted Benzenes

scholarly journals Theoretical Evaluation on The Interaction Between Triglycerides and Methylxanthines Using Density Functional Theory B3LYP/6-31G(d,p) and Molecular Electrostatic Potential

2020 ◽  
Vol 33 (1) ◽  
pp. 171-178
Author(s):  
N.F.M. Azmi ◽  
R. Ali ◽  
A.A. Azmi ◽  
M.Z.H. Rozaini ◽  
K.H.K. Bulat ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Basis Set ◽  
Individual Species ◽  
Interaction Energies ◽  
Binding Interaction ◽  
Functional Theory

The binding, interaction and distortion energies between the main triglycerides, palmitic-oleic-stearic (POS) in cocoa butter versus palmitic-oleic-palmitic (POP) in refined, bleached and deodorized (RBD) palm oil with cocoa′s methylxanthines (caffeine, theobromine, and theophylline) during the production of chocolate were theoretically studied and reported. The quantum mechanical software package of Gaussian09 at the theoretical level of density functional theory B3LYP/6-31G(d,p) was employed for all calculations, optimization, and basis set superposition errors (BSSE). Geometry optimizations were carried out to the minimum potential energy of individual species and binary complexes formed between the triglycerides, methylxanthines and polyphenols. The interaction energies for the optimized complexes were then corrected for the BSSE using the counterpoise method of Boys and Bernardi. The results revealed that the binding energy and interaction energy between methylxanthine components in cocoa powder with triglycerides were almost of the same magnitude (13.6-14.5 and 3.4-3.7 kJ/mol, respectively), except for the binary complex of POS-caffeine (25.1 and 10.7 kJ/mol, respectively). Based on the molecular geometry results, the hydrogen bond length and angle correlated well with the interaction energies. Meanwhile, the POS-caffeine complex with two higher and almost linear bond angles showed higher binding and interaction energies as compared to the other methylxanthines. Therefore, a donor-acceptor analysis showed that the hydrogen bond strength was proven using the molecular electrostatic potential (MEP), which resulted in parallel outcomes. The research results were believed to be one of the factors that contributed to the rheological behaviour and sensory perception of cocoa products, especially chocolate.

Implementation of the Molecular Electrostatic Potential over GPUs: Large Systems as Main Target

2020 ◽  
pp. 149-173
Author(s):  
J. César Cruz ◽  
Ponciano García-Gutierrez ◽  
Rafael A. Zubillaga ◽  
Rubicelia Vargas ◽  
Jorge Garza
Keyword(s):  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Main Target ◽  
Large Systems

Molecular Electrostatic Potential and Electron Density Topography:  Structure and Reactivity of (substituted arene)Cr(CO)3Complexes

2000 ◽  
Vol 19 (16) ◽  
pp. 3008-3015 ◽  
Author(s):  
C. H. Suresh ◽  
Nobuaki Koga ◽  
Shridhar R. Gadre
Keyword(s):  
Electron Density ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential

Intermolecular interactions, charge-density distribution and the electrostatic properties of pyrazinamide anti-TB drug molecule: an experimental and theoretical charge-density study

2014 ◽  
Vol 70 (3) ◽  
pp. 568-579 ◽  
Author(s):  
Gnanasekaran Rajalakshmi ◽  
Venkatesha R. Hathwar ◽  
Poomani Kumaradhas
Keyword(s):  
Charge Density ◽  
Electron Density ◽  
Intermolecular Interactions ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Direct Methods ◽  
Hirshfeld Surface ◽  
Basis Set ◽  
Total Electron Density ◽  
Total Electron

An experimental charge-density analysis of pyrazinamide (a first line antitubercular drug) was performed using high-resolution X-ray diffraction data [(sin θ/λ)max= 1.1 Å−1] measured at 100 (2) K. The structure was solved by direct methods usingSHELXS97 and refined bySHELXL97. The total electron density of the pyrazinamide molecule was modeled using the Hansen–Coppens multipole formalism implemented in theXDsoftware. The topological properties of electron density determined from the experiment were compared with the theoretical results obtained fromCRYSTAL09at the B3LYP/6-31G** level of theory. The crystal structure was stabilized by N—H...N and N—H...O hydrogen bonds, in which the N3—H3B...N1 and N3—H3A...O1 interactions form two types of dimers in the crystal. Hirshfeld surface analysis was carried out to analyze the intermolecular interactions. The fingerprint plot reveals that the N...H and O...H hydrogen-bonding interactions contribute 26.1 and 18.4%, respectively, of the total Hirshfeld surface. The lattice energy of the molecule was calculated using density functional theory (B3LYP) methods with the 6-31G** basis set. The molecular electrostatic potential of the pyrazinamide molecule exhibits extended electronegative regions around O1, N1 and N2. The existence of a negative electrostatic potential (ESP) region just above the upper and lower surfaces of the pyrazine ring confirm the π-electron cloud.

Closo-Boranes, -Carboranes, and -Silaboranes: A Topographical Study Using Electron Density and Molecular Electrostatic Potential

1994 ◽  
Vol 98 (26) ◽  
pp. 6445-6451 ◽  
Author(s):  
Eluvathingal D. Jemmis ◽  
G. Subramanian ◽  
Indira H. Srivastava ◽  
Shridhar R. Gadre
Keyword(s):  
Electron Density ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential
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