Methods & validation

Check the calculations and see where each model applies.

Check the calculations

Agreement with xraydb

Comparing with xraydb…

What the results mean

Tabulated atomic data. XrayDB / Elam data give absorption backgrounds and edge jumps for H to Cf, 100 $eV$ to 100 $keV$ .
Teaching spectra. Adjustable peaks and edge shifts are models, not measured data.
Quantum response. The browser solves a small Hamiltonian. It does not predict a material spectrum.
Imported curves. Raw arrays and your notes are preserved. Origin and calibration are unverified.

A passing check means the equations were solved correctly. It does not mean they are the right equations for your sample.

Claims we do not make

The quantum curve is the response of whichever Hamiltonian is loaded. That alone does not make it the XAS of a material or of a Mn K-edge.
This lab does not reproduce the papers’ spectra, active spaces or resource estimates.
These calculations run classically. They show no hardware result or quantum advantage.
State fidelity does not measure spectral accuracy. $L^{1}$ and RMSE here are app diagnostics.
A model edge shift does not measure lithium content or oxidation state.
The model ripples cannot give bond lengths. The pre-edge is not a pure dipole $1 s \to 3 d$ transition.
A model sweep is not operando data and cannot diagnose oxygen redox or degradation.
A high similarity score does not validate a model. Imported measurements and calibration are unverified.

Research references

The anchor papers simulate the oxygen K-edge of a $L i_{4} M n_{2} O$ cluster. The Mn teaching spectrum here is a separate example.

Simulating X-ray absorption spectroscopy of battery materials on a quantum computerFomichev et al., 2024
The time-domain workflow and oxygen-centred cluster example.
Fast simulations of X-ray absorption spectroscopy for battery materials on a quantum computerFomichev et al., 2025
Sampling, eigenvalue error and fault-tolerant cost estimates.
Demonstration of logical quantum phase estimation for X-ray absorption spectraNishi et al., 2025
$Fe L_{2, 3}$ edges, trapped-ion calculations and Lorentzian post-processing.
Quantum algorithm for simulating resonant inelastic X-ray scattering in battery materialsLoaiza et al., 2026
RIXS extends the absorption problem; it is outside this lab.
Practical Estimation of Trotter Error for Hamiltonian SimulationMaxwell et al., 2026
Why peak shifts can matter more than state fidelity.
Theory and practice of Trotter product formulas for quantum chemistryCasares et al., 2026
Improved product formulas; this lab uses first order.
Role of symmetry-forbidden transitions in resonant inelastic X-ray scattering emission from materials with trapped molecular O₂Radin and Kunitsa, 2025
Context for oxygen-edge studies of lithium-rich cathodes.
Insights on the volume variation of LiCoxMn2-xO4 electrode upon cycling: a correlative operando XRD and XAS studyMahayoni et al., 2026
Measured cycling data as context for the battery example.
Benchmark of First-Principles Titanium K-Edge X-Ray Absorption Spectral Simulations on Titanium-containing OxidesCao et al., 2026
Motivates comparing several similarity scores over a stated energy window.

Limits and further work

Material predictions need a structure, an active space, a core-excited Hamiltonian and calibrated reference spectra. Check convergence before comparing with a measurement.

Dense matrix storage grows as $4^n$ . The browser solver is limited to six qubits. Its gate counts exclude state preparation, measurement and error correction.

\text{model error} \neq \text{numerical error}

\text{counting noise} \neq \text{systematic uncertainty}