Comparison of ab Initio and DFT Electronic Structure Methods for Peptides Containing an Aromatic Ring:  Effect of Dispersion and BSSE

2007 ◽  
Vol 111 (50) ◽  
pp. 13272-13277 ◽  
Author(s):  
Ashley E. Shields ◽  
Tanja van Mourik
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Aromatic Ring ◽  
Electronic Structure Methods ◽  
Ab Initio And Dft ◽  
Ring Effect

scholarly journals Ab initio thermodynamic properties and their uncertainties for crystalline α-methanol

2017 ◽  
Vol 19 (44) ◽  
pp. 29940-29953 ◽  
Author(s):  
Ctirad Červinka ◽  
Gregory J. O. Beran
Keyword(s):  
Electronic Structure ◽  
Low Temperature ◽  
Thermodynamic Properties ◽  
Ab Initio ◽  
Molecular Crystals ◽  
Electronic Structure Methods

To investigate the performance of quasi-harmonic electronic structure methods for modeling molecular crystals at finite temperatures and pressures, thermodynamic properties are calculated for the low-temperature α polymorph of crystalline methanol and their computational uncertainties are analyzed.

scholarly journals Novel organic material with potential NLO application - electronic and spectroscopic properties

2008 ◽  
Vol 6 (4) ◽  
pp. 592-599 ◽  
Author(s):  
B.B. Koleva ◽  
T. Kolev ◽  
R. Nikolova ◽  
Y. Zagraniarsky ◽  
M. Spiteller
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Ir Spectroscopy ◽  
Ab Initio ◽  
Organic Material ◽  
Spectroscopic Properties ◽  
Thermal Methods ◽  
Polarized Ir Spectroscopy ◽  
Cosy Nmr ◽  
Ab Initio And Dft

AbstractNovel dicyanoisophorone derivative, (E)-2-(3-(4-aminostyryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile, is synthesized and its structure elucidated by means of conventional and linear polarized IR-spectroscopy of oriented colloids in nematic host, 1H, 13C, 1H, 1H-COSY NMR, HPLC tandem ESI MS-MS spectrometry, UV-VIS and thermal methods. Ab initio and DFT level of theory are used to theoretically obtain the electronic structure and optical properties, both in ground and exited state, of the compound.

scholarly journals Ab initio and semi-empirical Molecular Dynamics simulations of chemical reactions in isolated molecules and in clusters

2014 ◽  
Vol 16 (21) ◽  
pp. 9760-9775 ◽  
Author(s):  
R. B. Gerber ◽  
D. Shemesh ◽  
M. E. Varner ◽  
J. Kalinowski ◽  
B. Hirshberg
Keyword(s):  
Molecular Dynamics ◽  
Electronic Structure ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Chemical Reactions ◽  
Recent Progress ◽  
Electronic Structure Methods ◽  
Dynamics Simulations ◽  
Semi Empirical ◽  
Trajectory Simulations

Recent progress in “on-the-fly” trajectory simulations of molecular reactions, using different electronic structure methods is discussed, with analysis of the insights that such calculations can provide and of the strengths and limitations of the algorithms available.

Electronic Structure and Chemical Bonding in the OTi–N2Complexes: A Systematic ab Initio and DFT Study

2013 ◽  
Vol 117 (21) ◽  
pp. 4462-4471 ◽  
Author(s):  
Asma Marzouk ◽  
Bruno Madebène ◽  
M. Esmaïl Alikhani
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Chemical Bonding ◽  
Dft Study ◽  
Ab Initio And Dft

MODELING THE GROUND STATE GEOMETRY AND ESTIMATING THE CHARGE TRANSFER TRANSITION ENERGY OF THE TOLUENE–ICl MOLECULAR COMPLEX BY AB INITIO AND DFT METHODS

2008 ◽  
Vol 07 (03) ◽  
pp. 331-346 ◽  
Author(s):  
AMIT S. TIWARY ◽  
PARTHA SARATHI SENGUPTA ◽  
ASOK K. MUKHERJEE
Keyword(s):  
Charge Transfer ◽  
Binding Energy ◽  
Ab Initio ◽  
Aromatic Ring ◽  
Ground State ◽  
Density Functional ◽  
Transition Energy ◽  
Basis Set ◽  
Basis Set Superposition Error ◽  
Ab Initio And Dft

Out of several plausible isomeric structures of the toluene–ICl charge transfer (CT) complex, the most feasible one was determined by a detailed ab initio and DFT study at the HF, B3LYP, and mPW1PW91 levels using 6-31++G(d, p) basis set. Potential energy surface scans were performed with six possible structures ( I and Cl facing the o-, m-, and p-carbon atoms of toluene separately); the structures at the local minima of the surfaces were subjected to frequency calculation and the ones having no negative frequency were accepted as the real structure in the ground state. These structures were then subjected to full optimization. It was observed that the I – Cl bond, with its I atom oriented toward the aromatic ring, stands vertically above a C -atom at the ortho or para positions, being inclined at about 9° to the line perpendicular to the aromatic ring. Complexation increases the I – Cl bond length. After correction for basis set superposition error through a counterpoise calculation, we conclude from the binding energy that the preferred structure is the one with ICl above the ortho C atom. The calculated binding energy closely matches the experimental free energy of complexation. The electronic CT transition energy (hν CT ) with this structure in the ground state was calculated in vacuo by the restricted configuration interaction singlets method and in carbontetrachloride medium by the time dependent density functional theory method under the polarizable continuum model. The value of hν CT obtained from the ground-to-excited state transition electric dipole moments of the complex, is close to (somewhat underestimated) the reported experimental value.

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