Extracting Thermochemical Information from ab Initio Data Part 2

Unique considerations for ab initio thermochemistry

Absolute energies

Reaction scheme is important

Most heats of formation are not really “ab initio”

Total molecular energy?

Total atomization energy?

Isogyric reactions

Isogyric reaction #1

Isogyric reaction #2

Be a chemist!

Isodesmic reactions

Isodesmic reaction #1

A test for correlation balance

Isodesmic reaction #2

Isodesmic reaction #3

Homodesmic reaction

How reliable are the results?

Wavefunction diagnostics are needed

Future precision bottlenecks

Future scope

Summary (when reading critically or doing)