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Calculator

The calculator is the main interface at /calculate.

Workflow

  1. Upload a structure — drag-and-drop a .xyz, .cif, .poscar, or .pdb file, or pick one from the built-in ml-peg catalog (14 benchmark structures across 5 categories)
  2. Configure parameters — select model, calculation type, and physics settings
  3. Run — click Calculate and wait for results
  4. Explore — browse the five-tab metrics dashboard (Summary, Forces, Energy, Structure, Raw Data)
  5. Share — click Share Result to generate a permanent MACE Link

Structure input

The parser auto-detects format from the file extension and extracts:

  • Atom count and element list
  • Chemical formula
  • Bounding box dimensions
  • Lattice vectors (if periodic)
  • Reference energies/forces from extended XYZ metadata

Warning

Large structures (>500 atoms) may be slow. Multi-frame files use only the first frame.

Model selection

Model Use for Elements
MACE-MP-0 Materials, crystals, surfaces, bulk 89 elements
MACE-OFF Organic molecules H, C, N, O, F, P, S, Cl, Br, I
Custom Upload your own .model file Depends on training

Each model is available in small (fastest), medium (default), and large (most accurate).

Calculation types

Single-point energy & forces

Computes the energy and forces at the current geometry. No optimization.

Geometry optimization

Relaxes atomic positions using the BFGS algorithm until forces are below the threshold (fmax).

Parameter Default Recommended
fmax 0.05 eV/A 0.01 for production, 0.005 before frequency calculations
maxOptSteps 500 Increase for large/difficult systems

Molecular dynamics

Runs a trajectory with the selected ensemble:

Ensemble Thermostat Requirements
NVE None (microcanonical) Any system
NVT Langevin Temperature required
NPT Nose-Hoover + barostat Temperature, pressure, and periodic cell required

Velocities are initialized with Maxwell-Boltzmann distribution at the target temperature.

D3 Dispersion correction

Adds Grimme's DFT-D3 van der Waals correction on top of MACE-MP-0 predictions. Important for layered materials, molecular adsorption, and molecular crystals.

Danger

Never enable D3 with MACE-OFF. MACE-OFF was trained on wB97M-D3BJ data that already includes dispersion. Enabling D3 double-counts the correction.

Precision

  • float32 — default, fast, sufficient for energies and forces
  • float64 — required for vibrational analysis / Hessian calculations

Results

The metrics dashboard provides five tabs:

  • Summary — total energy, energy/atom, max force, RMS force, calculation time
  • Forces — per-atom force table, force magnitude chart
  • Energy — energy convergence (optimization) or energy vs. time (MD)
  • Structure — 3D viewer with force vector overlays
  • Raw Data — full JSON result for copy/export