Non-Local Density Functional Calculations of Gas Phase Heats of Formation
Abstract
A general procedure is presented for computing the gas phase heats of formation of a wide variety of organic compounds. Delta E for the formation. of the molecule from its elements at O deg K is obtained from density functional calculations (Gaussian 92/DFT) for optimized geometries. This result is converted to delta H at 298 deg K by assuming ideal behavior and adding the translational, rotational and vibrational energies. Additive correction terms corresponding to the various coordination states of the carbons, nitrogens and oxygens were developed using a data base of 54 compounds. The experimental delta h deg sub f values of these compounds are then reproduced with an average absolute error of 3 kcal/mole and a standard deviation of 4 kcal/mole. For a group of ten test cases that were not part of the data base, the average absolute error is 3.5 kcal/mole and the standard deviation is 4.1 kcal/mole. Gas phase heats of formation, Density functional calculations, Organic compounds.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 03, 1994
- Accession Number
- ADA286213
Entities
People
- Dariush Habibollahzadeh
- Jane S. Murray
- M. Edward Grice
- Monica G. Concha
- Peter Politzer
Organizations
- University of New Orleans