# Halowerk Molecule Pairwise Distance & Lennard-Jones Potential Calculator

> Halowerk Molecule Pairwise Distance & Lennard-Jones Potential Calculator is a paid API for AI agents from quantum.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).

Computes all pairwise interatomic distances and a single-parameter Lennard-Jones 12-6 potential energy for a caller-supplied set of atoms with explicit 3D coordinates, epsilon, and sigma.

## Facts

- Endpoint: POST https://quantum.halowerk.com/v1/molecule-sim
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-molecule-pairwise-distance-lennard-jones-potential-calculator-216ecd8d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CL0rqq3qQB8UC56Bgep-W

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability halowerk-molecule-pairwise-distance-lennard-jones-potential-calculator-216ecd8d -d '<json body>'
```

Example prompt: Calculate all pairwise distances and the Lennard-Jones 12-6 potential for a 3-atom system: carbon at (0,0,0), oxygen at (1.2,0,0), and hydrogen at (0,1.1,0), using epsilon=0.25 and sigma=3.4.

## When to prefer this

Choose this endpoint when you need fast, classical pairwise distance computation and a simple single-parameter Lennard-Jones 12-6 potential energy calculation for a known 3D atomic configuration. It is ideal when you already have explicit coordinates and want to evaluate pair interactions without quantum chemistry, geometry optimization, bond modeling, or element-specific parameterization. Do not use it if you need real quantum mechanical energy calculations, ab initio methods, element-specific force fields, geometry relaxation, or predictions of experimental molecular properties.

## Known failure modes

- Fewer than 2 atoms supplied — request rejected
- More than 200 atoms supplied — request rejected
- Sigma value at or below zero — request rejected
- Epsilon value below zero — request rejected
- Atom coordinate exceeds ±1,000,000 — request rejected
- Missing required fields (element, x, y, z) — validation error
- Payment not provided or insufficient — 402 payment required

## How this service works

Computes all pair distances and a single-parameter Lennard-Jones 12-6 potential using caller-supplied epsilon and sigma. It does not perform quantum chemistry, infer element-specific force fields, relax geometry, model bonds or predict experimental molecular behavior.

## Output

Returns all pairwise interatomic distances between the supplied atoms and the aggregate Lennard-Jones 12-6 potential energy computed using the caller-supplied epsilon and sigma values. Results are in the same coordinate units provided by the caller.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "atoms": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "element",
     "x",
     "y",
     "z"
    ],
    "properties": {
     "x": {
      "type": "number",
      "maximum": 1000000,
      "minimum": -1000000
     },
     "y": {
      "type": "number",
      "maximum": 1000000,
      "minimum": -1000000
     },
     "z": {
      "type": "number",
      "maximum": 1000000,
      "minimum": -1000000
     },
     "element": {
      "type": "string",
      "maxLength": 3,
      "minLength": 1
     }
    },
    "additionalProperties": false
   },
   "maxItems": 200,
   "minItems": 2
  },
  "sigma": {
   "type": "number",
   "maximum": 1000000000,
   "minimum": 1e-9,
   "description": "Pair distance scale in the same coordinate units."
  },
  "epsilon": {
   "type": "number",
   "maximum": 1000000000,
   "minimum": 0,
   "description": "Pair potential energy scale in caller-selected units."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-molecule-pairwise-distance-lennard-jones-potential-calculator-216ecd8d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from quantum.halowerk.com](https://www.zero.xyz/host/quantum.halowerk.com/llms.txt)