engleski

Calculated enthalpies of formation for molecules containing hydrogen, bromide and some first and second row atoms

In this work simple protocols are descibed in order to convert ab initio energies to accurate heats of formation for molecules containing carbon, hydrogen, oxygen, nitrogen, fluorine, chlorine, bromine, silicon, sulphur and phosphorus atoms. Protocols are developed and tested on data set of large number of compounds including planar and non planar, acyclic, cyclic and polycyclic, alcohols, aldehydes, ketones, acids, ethers, peroxides, anhydrides, lactones, oxides, etc. Enthalpies of formation are calculated with method of linear regression for previously calculated energies. Energies are calculated by semiempirical AM1 method, and ab initio HF and DFT B3LYP methods on various bassis sets. The experimental heat of formation covers a wide range of energy. Minimal difference in experimental and calculated heat of formation obtained in the described procedure was 2 kcal/mol.

ab initio ; DFT ; heat of formation

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