> ## Documentation Index > Fetch the complete documentation index at: https://docs.revilico.bio/llms.txt > Use this file to discover all available pages before exploring further. # Start a RevTorsion run > Relaxed scans of a bond, angle or dihedral: the energy profile across a grid, each point optimised with the coordinate held fixed. Starts a run and returns it with status `queued`; poll GET /v1/runs/{runId} until it finishes. Runs spend credits. **Limits:** `maxGridPoints`: 30, `maxAtoms`: 200, `maxConstraints`: 10. How the engine works and how to read its results: [RevTorsion documentation](/docs/revtorsion). **Scope:** `runs:write`. ## OpenAPI ````yaml /api-reference/openapi.json post /v1/engines/revtorsion/runs openapi: 3.1.0 info: title: Revilico API version: 1.0.0 description: >- Run Revilico's computational chemistry and biology engines from your own code: upload input files, start runs, follow them and read their results. servers: - url: https://public-api.revilico.bio security: - bearerAuth: [] tags: - name: Account description: Who you are, your credits and what your runs have used. - name: Engines description: The engines you can run, their parameter schemas and examples. - name: Files description: 'Upload input files: create an upload, then PUT the bytes.' - name: Runs description: Start, follow and cancel engine runs. - name: Results and outputs description: 'Read what a run produced: results, files and outputs.' - name: Projects description: Group runs into the projects you see in the web app. - name: Engine runs description: >- Start a run of one engine, with that engine's parameters and input files. Same endpoint as **Start a run**. - name: Health description: Service status. Needs no API key. paths: /v1/engines/revtorsion/runs: post: tags: - Engine runs summary: Start a RevTorsion run description: >- Relaxed scans of a bond, angle or dihedral: the energy profile across a grid, each point optimised with the coordinate held fixed. Starts a run and returns it with status `queued`; poll GET /v1/runs/{runId} until it finishes. Runs spend credits. **Limits:** `maxGridPoints`: 30, `maxAtoms`: 200, `maxConstraints`: 10. How the engine works and how to read its results: [RevTorsion documentation](/docs/revtorsion). **Scope:** `runs:write`. operationId: engineRuns.revtorsion requestBody: required: true content: application/json: schema: type: object properties: name: description: A name for the run, shown in the web app. type: string maxLength: 200 parameters: type: object properties: scan: type: object properties: coordinate: type: string enum: - bond - angle - dihedral description: >- bond (2 atoms, Å), angle (3 atoms, degrees) or dihedral (4 atoms, degrees). atoms: minItems: 2 maxItems: 4 type: array items: type: integer minimum: 1 maximum: 9007199254740991 description: 1-based atom indices defining the coordinate. start: type: number description: First value of the coordinate. stop: type: number description: Last value of the coordinate. num: type: integer minimum: 2 maximum: 30 description: Number of grid points, start and stop included. required: - coordinate - atoms - start - stop - num additionalProperties: false description: The coordinate to scan and its grid. constraints: default: [] description: Other coordinates to hold fixed at every grid point. maxItems: 10 type: array items: type: object properties: coordinate: type: string enum: - bond - angle - dihedral description: >- bond (2 atoms, Å), angle (3 atoms, degrees) or dihedral (4 atoms, degrees). atoms: minItems: 2 maxItems: 4 type: array items: type: integer minimum: 1 maximum: 9007199254740991 description: 1-based atom indices defining the coordinate. value: default: null description: >- Value to hold it at; null holds it at its value in the input. type: - number - 'null' required: - coordinate - atoms additionalProperties: false charge: default: 0 type: integer minimum: -10 maximum: 10 multiplicity: default: 1 type: integer minimum: 1 maximum: 11 settings: default: {} type: object properties: backend: default: aimnet2 description: >- aimnet2 (fast neural network, closed-shell organics only), gfn2-xtb / gfn1-xtb (semiempirical, H-Rn, open-shell), or dft (GPU, most accurate, slowest). type: string enum: - aimnet2 - gfn2-xtb - gfn1-xtb - dft model: default: null description: >- DFT functional (dft backend only); null picks r2scan-d4. anyOf: - type: string enum: - r2scan-d4 - wb97m-d3bj - type: 'null' basis: default: def2-svp description: >- DFT basis set; must stay def2-svp for the other backends. type: string enum: - def2-svp - pcseg-1 - def2-tzvp precision: default: float32 type: string enum: - float32 - float64 optimizer_mode: default: standard type: string enum: - draft - standard - fine - ultrafine - exhaustive max_optimizer_steps: default: 250 type: integer minimum: 1 maximum: 2000 wavefront_propagation: default: true description: >- Start each point from its neighbour’s optimised geometry. type: boolean energy_improvement_hartree: default: 0.000001 type: number exclusiveMinimum: 0 additionalProperties: false required: - scan additionalProperties: false inputs: type: object properties: structure: type: string description: >- One molecule with 3D coordinates: XYZ, SDF, MOL or MOL2 (up to 200 atoms). A file id (`file_…`). Formats: xyz, sdf, mol, mol2; up to 10 MB. required: - structure additionalProperties: false budget: description: Most credits the run may spend; it is stopped beyond that. type: number exclusiveMinimum: 0 projectId: description: >- Add the run to this project (`proj_…`); needs editor or owner on it. type: string required: - parameters - inputs additionalProperties: false examples: dihedral-scan: summary: A 360° torsion profile in 15° steps with AIMNet2. value: name: C1-C2 torsion profile parameters: scan: coordinate: dihedral atoms: - 1 - 2 - 3 - 4 start: -180 stop: 180 num: 25 inputs: structure: file_… bond-stretch-dft: summary: >- A bond stretch with DFT (r2SCAN-D4/def2-SVP), holding a dihedral fixed. value: parameters: scan: coordinate: bond atoms: - 1 - 2 start: 1.2 stop: 2.4 num: 13 constraints: - coordinate: dihedral atoms: - 3 - 1 - 2 - 4 value: null settings: backend: dft inputs: structure: file_… responses: '202': description: OK content: application/json: schema: $ref: '#/components/schemas/Run' '400': $ref: '#/components/responses/400' '401': $ref: '#/components/responses/401' '402': $ref: '#/components/responses/402' '403': $ref: '#/components/responses/403' '404': $ref: '#/components/responses/404' '422': $ref: '#/components/responses/422' '500': $ref: '#/components/responses/500' '502': $ref: '#/components/responses/502' components: schemas: Run: type: object properties: id: type: string description: Run id, `run_…`. engine: type: string description: Engine slug, e.g. `revredox`. name: type: - string - 'null' status: type: string enum: - queued - running - succeeded - failed - cancelled description: >- queued until the engine picks the run up; succeeded, failed and cancelled are final. statusReason: description: >- Why a cancelled run stopped: `user`, `insufficient_credits` or `budget_exceeded`. Null otherwise. type: - string - 'null' progress: type: number description: Progress the engine reports; 0 until it reports any. createdAt: type: string format: date-time startedAt: anyOf: - type: string format: date-time - type: 'null' endedAt: anyOf: - type: string format: date-time - type: 'null' budget: description: Most credits the run may spend, if one was set. type: - number - 'null' creditsUsed: type: number description: Credits charged to the run so far. error: anyOf: - type: object properties: message: type: string required: - message - type: 'null' description: Set when status is failed. links: type: object propertyNames: type: string additionalProperties: type: string description: 'Related endpoints: self, inputs, results, outputs, files.' warnings: description: >- Set when the run was created but a follow-up step, such as adding it to a project, failed. type: array items: type: string required: - id - engine - name - status - statusReason - progress - createdAt - startedAt - endedAt - budget - creditsUsed - error - links Error: type: object properties: error: type: object properties: code: type: string enum: - VALIDATION_FAILED - INVALID_ID - INVALID_PARAMETERS - INPUT_LIMIT_EXCEEDED - NOT_FOUND - FORBIDDEN - METHOD_NOT_ALLOWED - CONFLICT - PAYLOAD_TOO_LARGE - MISSING_CREDENTIALS - INVALID_CREDENTIALS - WRONG_ENVIRONMENT - CREDENTIALS_EXPIRED - CREDENTIALS_REVOKED - ACCOUNT_INACTIVE - API_ACCESS_NOT_ENABLED - INSUFFICIENT_SCOPE - SESSION_REQUIRED - TOO_MANY_AUTH_FAILURES - API_KEY_LIMIT_REACHED - ENGINE_NOT_ENABLED - DOCS_NOT_AVAILABLE - INSUFFICIENT_CREDITS - RUN_NOT_COMPLETE - ENGINE_SUBMIT_FAILED - RATE_LIMITED - SERVICE_UNAVAILABLE - INTERNAL_ERROR description: Stable within /v1; branch on this, not on the message. message: type: string description: Readable explanation, for people. details: description: >- Extra context, e.g. `issues` ({ path, message }[]) for validation errors. type: object propertyNames: type: string additionalProperties: {} required: - code - message required: - error responses: '400': description: >- The request is malformed. `error.code` is one of `VALIDATION_FAILED`, `INVALID_ID`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: VALIDATION_FAILED message: The request is malformed. '401': description: >- The API key is missing or not valid. `error.code` is one of `MISSING_CREDENTIALS`, `INVALID_CREDENTIALS`, `WRONG_ENVIRONMENT`, `CREDENTIALS_EXPIRED`, `CREDENTIALS_REVOKED`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: MISSING_CREDENTIALS message: The API key is missing or not valid. '402': description: >- Your organization doesn't have enough credits. `error.code` is one of `INSUFFICIENT_CREDITS`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: INSUFFICIENT_CREDITS message: Your organization doesn't have enough credits. '403': description: >- The key may not do this. `error.code` is one of `INSUFFICIENT_SCOPE`, `API_ACCESS_NOT_ENABLED`, `ENGINE_NOT_ENABLED`, `ACCOUNT_INACTIVE`, `FORBIDDEN`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: INSUFFICIENT_SCOPE message: The key may not do this. '404': description: Not found, or not visible to you. `error.code` is one of `NOT_FOUND`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: NOT_FOUND message: Not found, or not visible to you. '422': description: >- The parameters or input files don't fit the engine. `error.code` is one of `INVALID_PARAMETERS`, `INPUT_LIMIT_EXCEEDED`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: INVALID_PARAMETERS message: The parameters or input files don't fit the engine. '500': description: >- Something went wrong on our side. `error.code` is one of `INTERNAL_ERROR`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: INTERNAL_ERROR message: Something went wrong on our side. '502': description: >- The engine service rejected or failed the request. `error.code` is one of `ENGINE_SUBMIT_FAILED`. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: ENGINE_SUBMIT_FAILED message: The engine service rejected or failed the request. securitySchemes: bearerAuth: type: http scheme: bearer description: >- An API key from the web app (**Settings → Developer**), sent as `Authorization: Bearer rvl_live_…`. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.