A5013723871- Advanced Chemical Physics Studies
- Crystallography and molecular interactions
- Spectroscopy and Quantum Chemical Studies
- Atomic and Molecular Physics
- Chemical Thermodynamics and Molecular Structure
- Molecular spectroscopy and chirality
- Molecular Spectroscopy and Structure
- Various Chemistry Research Topics
- Computational Drug Discovery Methods
- Synthesis and Properties of Aromatic Compounds
- Free Radicals and Antioxidants
- Protein Structure and Dynamics
- Photochemistry and Electron Transfer Studies
- Advanced Physical and Chemical Molecular Interactions
- Molecular Junctions and Nanostructures
- Inorganic Fluorides and Related Compounds
- Machine Learning in Materials Science
- Mass Spectrometry Techniques and Applications
- Nonlinear Optical Materials Research
- History and advancements in chemistry
- DNA and Nucleic Acid Chemistry
- Electron and X-Ray Spectroscopy Techniques
- X-ray Diffraction in Crystallography
- Phase Equilibria and Thermodynamics
- Organic Chemistry Cycloaddition Reactions
Savitribai Phule Pune University
2010-2024
University Grants Commission
2020
Indian Institute of Technology Kanpur
2001-2017
Tohoku University
2017
Chhatrapati Shahu Ji Maharaj University
2015
Indian Institute of Technology Indore
2011
Indian Institute of Chemical Technology
2010
Institute for Molecular Science
2010
National Institute for Interdisciplinary Science and Technology
2007-2010
University of Houston
1981-2009
Extensive ab initio calculations have been performed using the 6-31G(d,p) and 6-311++G(2d,2p) basis sets for several possible structures of water clusters (H2O)n, n = 8−20. It is found that most stable geometries arise from a fusion tetrameric or pentameric rings. As result, 8, 12, 16, 20, are to be cuboids, while (H2O)10 (H2O)15 fused structures. For other (n 9, 11, 13, 14, 17−19) under investigation, can thought as arising either cuboid pentamers combination thereof. The stability some...
We report on the organization and outcome of fourth blind test crystal structure prediction, an international collaborative project organized to evaluate present state in computational methods predicting structures small organic molecules. There were 14 research groups which took part, using a variety generate rank most likely for four target systems: three single-component 1:1 cocrystal. Participants challenged predict systems, given only their molecular diagrams, while recently determined...
A linear-scaling scheme for estimating the electronic energy, gradients, and Hessian of a large molecule at ab initio level theory based on fragment set cardinality is presented. With this proposition, general, cardinality-guided molecular tailoring approach (CG-MTA) geometry optimization molecules implemented. The method employs energy gradients extracted from wave functions, enabling computations otherwise impractical PC hardware. Further, readily amenable to scale coarse-grain...
Near--Hartree-Fock information entropies ${S}_{\ensuremath{\rho}}$=-F\ensuremath{\rho}(r)ln\ensuremath{\rho}(r)dr and ${S}_{\ensuremath{\gamma}}$=-F \ensuremath{\gamma}(p)ln\ensuremath{\gamma}(p)dp, where \ensuremath{\rho}(r) \ensuremath{\gamma}(p) are one-electron densities in coordinate momentum space, respectively, have been computed for atoms their ground excited states. The the harmonic oscillator hydrogen atom as prototype systems also discussed. result of this exercise is a numerical...
The topography of the molecular electrostatic potential (MESP) is studied for some small neutral molecules and OH− ion. Different kinds critical points (CP’s) rank 3 are identified their occurrences discussed. correlation these CP’s with structure brought out. Bond ellipticities determined in terms curvatures bond CP’s. These show trends similar to those reported by Bader et al. [J. Am. Chem. Soc. 105, 5061 (1983)]. A typical example illustrates existence a degenerate nonisolated ring CP’s,...
A LOCAL DENSITY FUNCTIONAL THEORY OF THE GROUND ELECTRONIC STATES ATOMS AND MOLECULES IS GENERATED FROM THREE ASSUMPTIONS: (i) The energy functional is local. (ii) chemical potential of a neutral atom zero. (iii) atomic number Z -0.6127 Z(7/3). shown to have the form [Formula: see text] where A(0)=6.4563 and B(0)=1.0058. first term represents electronic kinetic energy, second electron-electron repulsion for N electrons, third nucleus-electron attraction energy. E electron density rho are...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSCRF calculation of the effect water on topology molecular electrostatic potentialF. J. Luque, M. Orozco, P. K. Bhadane, and S. R. GadreCite this: Phys. Chem. 1993, 97, 37, 9380–9384Publication Date (Print):September 1, 1993Publication History Published online1 May 2002Published inissue 1 September 1993https://pubs.acs.org/doi/10.1021/j100139a021https://doi.org/10.1021/j100139a021research-articleACS PublicationsRequest reuse permissionsArticle...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular Tailoring Approach for Simulation of Electrostatic PropertiesShridhar R. Gadre, Rajendra N. Shirsat, and Ajay C. LimayeCite this: J. Phys. Chem. 1994, 98, 37, 9165–9169Publication Date (Print):September 1, 1994Publication History Published online1 May 2002Published inissue 1 September 1994https://pubs.acs.org/doi/10.1021/j100088a013https://doi.org/10.1021/j100088a013research-articleACS PublicationsRequest reuse permissionsArticle...
Existence of strict local maxima within the molecular electrostatic potential (MESP) maps has been rigorously ruled out. The proof to this effect is based solely on classical Poisson equation. It further shown that at least one-directional negative-valued minimum in MESP for a negative ion must occur along any arbitrary direction. Under some special circumstances, an equipotential surface could exist such species. These results properly reduce their atomic counterparts proven by Politzer and...
The theorem proposed by Pathak and Gadre [J. Chem. Phys. 93, 1770 (1990)], that the electrostatic potential (ESP) of negative ions must exhibit a directional valued minimum along any arbitrary direction has been verified for some small molecular ions, viz., OH−, CN−, N−3, NO−3, NH−2. Also, as predicted [Proc. Ind. Acad. Sci. (Chem. Sci.) 102, 18 (1989)], ESP (MESP) maps are found to be devoid local maxima. As consequence, these reveal rich topographical details in form several saddle points...
Conspectus Chemistry on the scale of molecular clusters may be dramatically different from that in macroscopic bulk. Greater understanding chemistry this size regime could greatly influence fields such as materials science and atmospheric environmental chemistry. Recent advances experimental techniques computational resources have led to accurate investigations energies spectral properties weakly bonded clusters. These enabled researchers learn how physicochemical evolve individual molecules...
A clear-cut definition of lone pairs has been offered in terms characteristics minima molecular electrostatic potential (MESP). The largest eigenvalue and corresponding eigenvector the Hessian at are shown to distinguish pair regions from other types electron localization (such as π bonds). comparative study depicted by various scalar fields such Laplacian density function is made. Further, an attempt made generalize case cations.
Abstract The development of a linear‐scaling method, viz. “molecular tailoring approach” with an emphasis on accurate computation one‐electron properties large molecules is reported. This method based fragmenting the reference macromolecule into number small, overlapping similar size. density matrix (DM) parent molecule synthesized from individual fragment DMs, computed separately at Hartree–Fock (HF) level, and used for property evaluation. In effect, this reduces O( N 3 ) scaling order...
Informational entropies ${S}_{\ensuremath{\rho}}=\ensuremath{-}\ensuremath{\int}\ensuremath{\rho}\mathrm{ln}\ensuremath{\rho}d\stackrel{\ensuremath{\rightarrow}}{r}$ and ${S}_{\ensuremath{\gamma}}=\ensuremath{-}\ensuremath{\int}\ensuremath{\gamma}\mathrm{ln}\ensuremath{\gamma}d\stackrel{\ensuremath{\rightarrow}}{\mathrm{p}}$ have been computed from neutralatom Thomas-Fermi coordinate-space density $\ensuremath{\rho}$ momentum $\ensuremath{\gamma}$. These turn out to be...
In spite of many theoretical and experimental attempts for understanding intramolecular hydrogen bonding (H-bonding) in carbohydrates, a direct quantification individual H-bond energies the cooperativity among H-bonded networks has not been reported literature. The present work attempts, first time, estimation O−H···O interaction sugar molecules using recently developed molecular tailoring approach (MTA). estimated are range 1.2−4.1 kcal mol-1. It is seen that OH···O equatorial−equatorial...
An electrostatics-based approach has been proposed for probing the weak interactions between lone pair containing molecules and π deficient molecular systems. For electron-rich molecules, negative minima in electrostatic potential (MESP) topography give location of electron localization MESP value at minimum (Vmin) quantifies character that region. Interactive behavior a bearing molecule with π-systems, such as hexafluorobenzene, 1,3,5-trinitrobenzene, 2,4,6-trifluoro-1,3,5-triazine...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronegativities of the elements from simple .CHI..alpha. theoryLibero J. Bartolotti, Shridhar R. Gadre, and Robert G. ParrCite this: Am. Chem. Soc. 1980, 102, 9, 2945–2948Publication Date (Print):April 1, 1980Publication History Published online1 May 2002Published inissue 1 April 1980https://pubs.acs.org/doi/10.1021/ja00529a013https://doi.org/10.1021/ja00529a013research-articleACS PublicationsRequest reuse permissionsArticle...
The previously proposed molecular tailoring approached (MTA) [Deshmukh, M. M.; Gadre, S. R.; Bartolotti, L. J. Phys. Chem. A 2006, 110, 12519] for the estimation of intramolecular O−H···O hydrogen bond energy is extended to that N−H···O═C within polypeptides. methodology initially tested on a tetrapeptide containing two types bonds and found distinguish between them. estimated values are in good agreement with trends predicted by geometrical parameters. Furthermore, this applied partially as...
Water clusters (H2O)20 and (H2O)25 are explored at the Møller-Plesset second-order perturbation (MP2) level of theory. Geometry optimization is carried out on favorable structures, initially generated by temperature basin paving (TBP) method, utilizing fragment-based molecular tailoring approach (MTA). MTA-based stabilization energies complete basis set limit accurately estimated grafting energy correction using a smaller set. For prototypical cases, minima established via vibrational...
Tropolone, a 15-atom cyclic molecule, has received much interest both experimentally and theoretically due to its H-transfer tunneling dynamics. An accurate theoretical description is challenging owing the need develop high-level potential energy surface (PES) then simulate quantum-mechanical on this PES in full dimensionality. Here, we tackle aspects of challenge make detailed comparisons with experiments for numerous isotopomers. The PES, near CCSD(T)-quality, obtained using Δ-machine...