Chemistry Limitations
Documented FailuresOf 1,703 chemical phenomena tested, ~11% failed outright and many more showed only weak correlations. This page documents what doesn't work and why.
Failure Breakdown
Why These Fail
Channel Independence
γphonon, γelectron, and γopticaldon't correlate with each other. A material can have high phonon coherence (fast sound) but low electronic coherence (poor conductor). A single γ can't capture multi-channel behavior.
Spin-Orbit Coupling
Magnetic properties (susceptibility, Hall coefficient) are dominated by spin-orbit coupling, which has no representation in the coherence function. The γ parameter measures density-based correlations, not spin-based ones.
Boundary vs. Bulk
Surface phenomena (catalysis, adsorption, thermionic emission) depend on boundary conditions that differ from bulk properties. C(ρ) describes bulk coherence; boundary coherence follows different rules.
Mean-Field Limitations
The tanh form is a mean-field result. Near critical points, fluctuations dominate and mean-field theory fails. Critical exponents are 2× off because C(ρ) ignores fluctuations by construction.
What This Teaches
The coherence function is a classification tool, not a prediction engine. It tells you what regime a system is in (quantum/boundary/classical) and correlates well with bulk properties that depend on collective behavior (sound velocity, electronegativity). It fails for properties that depend on specific quantum details (spin, orbital structure, crystal symmetry).
This is an honest limitation, not a failure of the research program. Understandingwhere your theory applies and where it doesn't is as valuable as the theory itself.