scholarly journals Shermo: A General Code for Calculating Molecular Thermochemistry Properties

2020 ◽  
Author(s):  
Tian Lu ◽  
qinxue chen
Keyword(s):  
Quantum Chemistry ◽  
Harmonic Oscillator ◽  
Thermodynamic Data ◽  
Thermodynamic Quantities ◽  
Rigid Rotor ◽  
Low Frequencies ◽  
Frequency Scale ◽  
Scale Factors ◽  
Temperature And Pressure ◽  
Output Information

Calculation of molecular thermodynamic quantities is one of the most frequently involved task in daily quantum chemistry studies. In this article, we present a general, stand-alone, powerful and flexible code named Shermo for calculating various common thermochemistry data. This code is compatible with Gaussian, ORCA, GAMESS-US and NWChem and has many unique advantages: the output information is very easy to comprehend; thermodynamic quantities can be fully decomposed to contributions of various sources; temperature and pressure can be conveniently scanned; two quasi-rigid-rotor harmonic oscillator (quasi-RRHO) models are supported to properly deal with low frequencies; different frequency scale factors can be simultaneously specified for calculating different thermodynamic quantities; conformation weighted thermodynamic data can be directly evaluated; the code can be easily run and embedded into shell script. We hope the Shermo program will bring great convenience to quantum chemists. This code can be freely obtained at http://sobereva.com/soft/shermo.

scholarly journals Shermo: A General Code for Calculating Molecular Thermochemistry Properties

2020 ◽  
Author(s):  
Tian Lu ◽  
qinxue chen
Keyword(s):  
Quantum Chemistry ◽  
Harmonic Oscillator ◽  
Thermodynamic Data ◽  
Thermodynamic Quantities ◽  
Rigid Rotor ◽  
Low Frequencies ◽  
Frequency Scale ◽  
Scale Factors ◽  
Temperature And Pressure ◽  
Output Information

Calculation of molecular thermodynamic quantities is one of the most frequently involved task in daily quantum chemistry studies. In this article, we present a general, stand-alone, powerful and flexible code named Shermo for calculating various common thermochemistry data. This code is compatible with Gaussian, ORCA, GAMESS-US and NWChem and has many unique advantages: the output information is very easy to comprehend; thermodynamic quantities can be fully decomposed to contributions of various sources; temperature and pressure can be conveniently scanned; two quasi-rigid-rotor harmonic oscillator (quasi-RRHO) models are supported to properly deal with low frequencies; different frequency scale factors can be simultaneously specified for calculating different thermodynamic quantities; conformation weighted thermodynamic data can be directly evaluated; the code can be easily run and embedded into shell script. We hope the Shermo program will bring great convenience to quantum chemists. This code can be freely obtained at http://sobereva.com/soft/shermo.

Thermodynamic Data of Iodine Reactions Calculated by Quantum Chemistry. Training Set of Molecules

2008 ◽  
Vol 73 (10) ◽  
pp. 1340-1356 ◽  
Author(s):  
Katarína Mečiarová ◽  
Laurent Cantrel ◽  
Ivan Černušák
Keyword(s):  
Quantum Chemistry ◽  
Ab Initio ◽  
Thermodynamic Data ◽  
Theoretical Calculations ◽  
Reactor Core ◽  
Fission Products ◽  
Vapour Phase ◽  
Reactor Accident ◽  
Training Set ◽  
Coolant System

This paper focuses on the reactivity of iodine which is the most critical radioactive contaminant with potential short-term radiological consequences to the environment. The radiological risk assessments of 131I volatile fission products rely on studies of the vapour-phase chemical reactions proceeding in the reactor coolant system (RCS), whose function is transferring the energy from the reactor core to a secondary pressurised water line via the steam generator. Iodine is a fission product of major importance in any reactor accident because numerous volatile iodine species exist under reactor containment conditions. In this work, the comparison of the thermodynamic data obtained from the experimental measurements and theoretical calculations (approaching "chemical accuracy") is presented. Ab initio quantum chemistry methods, combined with a standard statistical-thermodynamical treatment and followed by inclusion of small energetic corrections (approximating full configuration interaction and spin-orbit effects) are used to calculate the spectroscopic and thermodynamic properties of molecules containing atoms H, O and I. The set of molecules and reactions serves as a benchmark for future studies. The results for this training set are compared with reference values coming from an established thermodynamic database. The computed results are promising enough to go on performing ab initio calculations in order to predict thermo-kinetic parameters of other reactions involving iodine-containing species.

STUDY OF THERMODYNAMIC PROPERTIES OF ZINC-BLENDE-TYPE SEMICONDUCTORS: TEMPERATURE AND PRESSURE DEPENDENCES

2011 ◽  
Vol 25 (12n13) ◽  
pp. 1041-1051 ◽  
Author(s):  
HO KHAC HIEU ◽  
VU VAN HUNG
Keyword(s):  
Nearest Neighbor ◽  
Thermodynamic Quantities ◽  
Atomic Displacements ◽  
Zinc Blende ◽  
The Mean ◽  
Temperature And Pressure ◽  
Analytical Expressions ◽  
Theoretical Results ◽  
Nearest Neighbor Distances ◽  
Statistical Moment Method

Using the statistical moment method (SMM), the temperature and pressure dependences of thermodynamic quantities of zinc-blende-type semiconductors have been investigated. The analytical expressions of the nearest-neighbor distances, the change of volumes and the mean-square atomic displacements (MSDs) have been derived. Numerical calculations have been performed for a series of zinc-blende-type semiconductors: GaAs , GaP , GaSb , InAs , InP and InSb . The agreement between our calculations and both earlier other theoretical results and experimental data is a support for our new theory in investigating the temperature and pressure dependences of thermodynamic quantities of semiconductors.

Evaluation of the Thermodynamic Data of CH3SiCl3 Based on Quantum Chemistry Calculations

2006 ◽  
Vol 35 (3) ◽  
pp. 1385-1390 ◽  
Author(s):  
Qingfeng Zeng ◽  
Kehe Su ◽  
Litong Zhang ◽  
Yongdong Xu ◽  
Laifei Cheng ◽  
...  
Keyword(s):  
Quantum Chemistry ◽  
Thermodynamic Data ◽  
Quantum Chemistry Calculations

scholarly journals GoodVibes: automated thermochemistry for heterogeneous computational chemistry data

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 291 ◽  
Author(s):  
Guilian Luchini ◽  
Juan V. Alegre-Requena ◽  
Ignacio Funes-Ardoiz ◽  
Robert S. Paton
Keyword(s):  
Harmonic Oscillator ◽  
Computational Chemistry ◽  
Open Source ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Basis Set ◽  
Partition Functions ◽  
Rigid Rotor ◽  
Computational Data ◽  
Publication Quality

GoodVibes is an open-source Python toolkit for processing the results of quantum chemical calculations. Thermochemical data are not simply parsed, but evaluated by evaluation of translational, rotational, vibrational and electronic partition functions. Changes in concentration, pressure, and temperature can be applied, and deficiencies in the rigid rotor harmonic oscillator treatment can be corrected. Vibrational scaling factors can also be applied by automatic detection of the level of theory and basis set. Absolute and relative thermochemical values are output to text and graphical plots in seconds. GoodVibes provides a transparent and reproducible way to process raw computational data into publication-quality tables and figures without the use of spreadsheets.

The pressure dependence of the dehydration of gypsum to bassanite

1987 ◽  
Vol 51 (361) ◽  
pp. 453-457 ◽  
Author(s):  
J. D. C. McConnell ◽  
D. M. Astill ◽  
P. L. Hall
Keyword(s):  
Elevated Temperature ◽  
Experimental Determination ◽  
Volume Change ◽  
Pressure Dependence ◽  
Thermodynamic Data ◽  
Dehydration Reaction ◽  
Temperature And Pressure ◽  
The Stability ◽  
Very High

AbstractA new experimental determination of the stability relationships for the dehydration of gypsum to the hemihydrate mineral bassanite at elevated temperature and pressure is described. The experimental method used depends on the observation of very small changes in pressure on the onset of reaction due to the potential volume change in the reaction. The technique yields P-T data of very high precision for this dehydration reaction, and the method is likely to be of use for other reactions. The experimental P-T results have been compared with those calculated from existing thermodynamic data for this reaction.

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