Accurate evaluation of combustion enthalpy by ab-intio computations

Area of Science:

• Computational chemistry
• Thermochemistry

Background:

• Accurate combustion enthalpy evaluation is crucial for science and industry.
• Ab-initio methods for combustion enthalpy are scarce and inconsistent with experimental data.

Purpose of the Study:

• Investigate inconsistencies in ab-initio combustion enthalpy predictions.
• Propose guidelines for high-accuracy ab-initio reaction enthalpy estimation.

Main Methods:

• Utilized DSD-PBEP86 double-hybrid density functional theory.
• Employed CCSD(T)-F12 coupled-cluster computations.

Main Results:

• Achieved highly accurate combustion enthalpy predictions for 40 organic molecules.
• Demonstrated mean unsigned errors below 0.5% compared to experimental data for both methods.

Conclusions:

• Established reliable ab-initio guidelines for precise combustion enthalpy calculations.
• Validated DSD-PBEP86 and CCSD(T)-F12 as accurate computational approaches.