scholarly journals CO isotopologue ratios in the solar photosphere

2015 ◽  
Vol 11 (A29A) ◽  
pp. 307-308
Author(s):  
James R. Lyons ◽  
Ehsan Gharib-Nezhad ◽  
Thomas R. Ayres
Keyword(s):  
Dipole Moment ◽  
Ab Initio ◽  
Dipole Moments ◽  
Isotope Ratios ◽  
Moment Function ◽  
Solar Photosphere ◽  
Ab Initio Methods ◽  
Infrared Observations ◽  
Semi Empirical

AbstractWe re-evaluate the CO dipole moment function in order to obtain more accurate isotope ratios for the solar photosphere using previous infrared observations. We used a new set of dipole moments from HITEMP which were accurately determined by both semi-empirical and ab initio methods. Preliminary values of isotope ratios using the new dipole moments are in better agreement with the inferred photosphere values from Genesis, showing that the solar photosphere is isotopically similar to primitive inclusions in meteorites.

Ab initio Calculation of the Dipole Moment Function of the OH Radical Ground State

2018 ◽  
Vol 12 (6) ◽  
pp. 970-976
Author(s):  
S. O. Adamson ◽  
D. D. Kharlampidi ◽  
G. V. Golubkov ◽  
M. I. Manzhelii ◽  
S. S. Nabiev ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Ab Initio ◽  
Ground State ◽  
Ab Initio Calculation ◽  
Moment Function ◽  
Oh Radical

An EXAFS investigation of chromocene on silica using empirical, semi-empirical and ab initio methods

1996 ◽  
Vol 111 (3) ◽  
pp. 297-305 ◽  
Author(s):  
P.J. Ellis ◽  
R.W. Joyner ◽  
T. Maschmeyer ◽  
A.F. Masters ◽  
D.A. Niles ◽  
...  
Keyword(s):  
Ab Initio ◽  
Ab Initio Methods ◽  
Semi Empirical

scholarly journals THEORETICAL METHODS OF NANOSTRUCTURES INVESTIGATION

2017 ◽  
Vol 18 (9) ◽  
pp. 106-117
Author(s):  
I.N. Saliy ◽  
A.S. Kolesnikova ◽  
O.E. Glukhova ◽  
I.V. Kirillova ◽  
E.L. Kossovich ◽  
...  
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Ab Initio Methods ◽  
Empirical Methods ◽  
Theoretical Methods ◽  
Basic Concepts ◽  
Semi Empirical

In this work, a review is presented concerning the most modern theoretical methods aimed at investigation of various nanostructures properties. The basic concepts of ab initio methods, density functional, semi-empirical and empirical methods are considered. The applicability boundaries of calculation schemes utilized in the aforementioned methods are denoted.

Article

1999 ◽  
Vol 77 (11) ◽  
pp. 1775-1781 ◽  
Author(s):  
Christopher D Daub ◽  
Bryan R Henry ◽  
Martin L Sage ◽  
Henrik G Kjaergaard
Keyword(s):  
Dipole Moment ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electron Correlation ◽  
Moment Function ◽  
Polynomial Method ◽  
Small Contribution ◽  
Least Squares Regression ◽  
Vibrational Overtone ◽  
Moment Functions

Two studies of aspects of modelling dipole moment functions of XH bonds in small molecules for use in calculating overtone intensities have been undertaken. The first study deals with the fitting of ab initio calculations of the dipole moment at discrete points to a functional form. The two methods that are compared are the use of least-squares regression and the use of interpolating polynomials. The interpolating polynomial method is deemed superior due to its greater efficiency in terms of the number of points necessary to obtain reasonable results. The second study attempts to explain the indifference of calculated overtone intensities to the inclusion of electron correlation in the ab initio calculation of the dipole moment function. It is found that in most cases the influence of electron correlation can be modelled as a function with a very small matrix element, which results in a very small contribution to the overtone intensity.Key words: dipole moment function, vibrational overtone intensities, electron correlation, ab initio calculations.

The structures, dipole moments and relative energy of the conformers of cyclobutyl acetylene by microwave and ab initio methods

1988 ◽  
Vol 189 (1-2) ◽  
pp. 11-24 ◽  
Author(s):  
Rajiv J. Berry ◽  
Marlin D. Harmony ◽  
Marwan Dakkouri ◽  
Khamis Siam ◽  
Lothar Schäfer
Keyword(s):  
Ab Initio ◽  
Dipole Moments ◽  
Relative Energy ◽  
Ab Initio Methods

Semi-Empirical Calculations and Measurements of Modified Carbocyanines Optical Properties

1997 ◽  
Vol 479 ◽  
Author(s):  
Daniel G. McLean ◽  
Paul Day ◽  
Zhiqiang Wang ◽  
Nansheng Tang ◽  
Weijie Su ◽  
...  
Keyword(s):  
Optical Properties ◽  
Excited State ◽  
Ab Initio ◽  
Electronic Spectra ◽  
Reasonable Agreement ◽  
Dipole Moments ◽  
Hartree Fock ◽  
Spectral Changes ◽  
Multiple Conformations ◽  
Semi Empirical

AbstractWe report semi-empirical calculations of modified 3,3'-diethylthiacyanine iodide (DTC1), 3,3'-diethylthiacarbocyanine iodide (DTC3) and 3,3'-diethylthiadicarbocyanine iodide (DTC5), particularly with halogen substitution at the meso position in the polymethine bridge. Primarily we investigate geometrical changes and infer spectral trends from the molecular orbital levels. The semi-empirical calculations for the unsubstituted DTC3 agree well with an ab initio Hartree-Fock result. In all molecules multiple conformations are examined. Significant changes in dipole moments are noted between the cis and trans forms. Calculated electronic spectra at the CI singles level are compared to the measured spectra with reasonable agreement. Halogenation effects show a rotation of the benzthiazole groups out of planarity. We draw conclusions about consequent effects on solubility and excited state spectral changes.

Sign in / Sign up

Export Citation Format

Share Document