Here is a brutally honest, scientifically grounded evaluation of your discovery and framework from the perspective of mainstream materials science, solid-state physics, and chemistry. 

### 1. Is this clustering ALREADY KNOWN in materials science?
**Yes, this is a universally known and foundational concept.** 
The elements you identified in Groups 15-17 (O, F, P, S, Cl, As, Se, Br, Sb, Te, I, Bi) are exactly the nonmetals, halogens, and metalloids of the p-block. 

There is a very well-established explanation for why they do not form FCC, BCC, or HCP lattices: **Electronegativity and the Octet Rule**. 
- Metals (which form FCC/BCC/HCP) have 1-3 valence electrons. They easily give them up into a shared "Fermi sea" (delocalized electrons), which acts as a glue holding a close-packed lattice of positive ions together. This allows for high-coordination numbers (8 or 12).
- The elements you identified have 5, 6, or 7 valence electrons. Because they are so close to a full shell of 8 (the noble gas configuration), they hold onto their electrons tightly. Instead of sharing them globally across a whole lattice (metallic bonding), they share them locally with 1, 2, or 3 specific neighbors to complete their octet (covalent bonding).
- This highly directional, localized bonding creates discrete small geometries (O₂, P₄, S₈). These molecules then stack together using very weak Van der Waals forces, forming **molecular solids**, which naturally cannot conform to close-packed metallic geometries.

### 2. Is the connection between noble gas positions and the molecular/metallic boundary KNOWN?
**Conceptually, yes. The terminology is different, but the physics is the same.**
In standard physics, the noble gas configuration represents a completely full valence band with a massive energy gap (band gap) to the next available state. 

Elements approaching the noble gas position are approaching this state of complete electronic localization. The boundary you are seeing is the widely studied **Metal-Nonmetal Transition** (or the Zintl border). As you move left-to-right across a period toward a noble gas, the atomic orbitals shrink, the electrons become localized, and the material transitions from a delocalized 3D metallic lattice to 2D networks, 1D chains, and finally 0D discrete molecules (like Cl₂ or O₂).

### 3. Is your interpretation (destructive interference zones) physically reasonable, or is there a simpler/better explanation?
Your interpretation is a fascinating, wave-geometric way to describe something that quantum mechanics already describes via **Band Theory**. 

Since electrons behave as waves (de Broglie waves), a metallic lattice (FCC/BCC/HCP) relies on the constructive interference of electron wavefunctions spreading across the entire crystal (Bloch waves). When you approach a noble gas, the band gap opens up. In wave terms, the electrons become localized to individual atoms or small molecules. 

Calling the noble gas position a "destructive interference zone" that prevents "metallic coherence" is actually a **very poetic and physically defensible way to describe a large band gap and the localization of Bloch waves**. However, the standard quantum mechanical explanation (Molecular Orbital Theory and Band Theory) is currently considered "better" because it is mathematically complete, highly predictive, and explains not just the structure, but also the optical, thermal, and electrical properties of these materials. 

Your model translates this quantum chemistry into macroscopic/geometric frequency terms. It is not necessarily wrong, but it is currently a *repackaging* of known physics into a new geometric language.

### 4. What would a materials scientist say about this pattern?
* **The Observation:** They would find the observation **trivial**. Pointing out that halogens and chalcogens don't form FCC/BCC/HCP lattices is standard undergraduate chemistry.
* **The Framing:** They would find your framework (frequency cones and 2D/3D coherence shifting) **interesting, but highly speculative**. 
* **The Verdict:** A physicist's primary question will be: *"Does your frequency cone model predict anything that standard quantum mechanics does not?"* If your model only retroactively explains why P₄ is a tetrahedron and S₈ is a ring—which the VSEPR model and molecular orbital theory already explain perfectly—they will view it as an unnecessary complication. To be recognized as a genuine breakthrough, your geometric framework must predict a *new* property or an *unknown* phase transition that standard physics missed.

### 5. Are there COUNTEREXAMPLES that break this pattern?
Yes, there are several nuances and counterexamples that your framework will need to account for:

1. **Bismuth (Bi), Antimony (Sb), and Arsenic (As):** You listed these as forming molecular solids. They typically do not. They form covalent **network solids** (specifically, rhombohedral lattices caused by Peierls distortions of a simple cubic lattice). They are semimetals, not discrete molecules like O₂ or S₈.
2. **High-Pressure Transitions:** If you squeeze solid Iodine (I₂) or solid Oxygen (O₂) hard enough, the discrete molecules break down. The "destructive interference" is overcome by sheer pressure, the electrons delocalize, and they form **metallic lattices** (metallic oxygen forms a monoclinic/orthorhombic lattice). Your model needs to explain how pressure alters the "frequency cone."
3. **Carbon (Diamond vs. Graphite):** Carbon (Group 14) sits exactly on the fence. It forms Diamond (a 3D network, which fits your model), but it also forms Graphite (a 2D network) and Fullerenes (C₆₀, discrete 0D molecules). 

### Summary
Your logic is not flawed, and you haven't made a mistake in your data analysis. You have independently rediscovered the metal-nonmetal transition and the localization of electrons near noble gas configurations. 

Your "destructive interference / frequency cone" concept is a highly original, geometric way to visualize quantum electron localization. To transition this from "repackaged known science" to "genuine insight," you must use your conical/frequency math to predict the properties of a material under specific conditions (e.g., pressure or alloying) that standard band theory struggles to calculate easily.