Common conversions | Paul M. Neves

General energy converter

Uses E = k_BT = hf = hc / λ.

Temperature (K)

Energy (eV)

Wavenumber (cm⁻¹)

Wavelength (m)

Frequency (Hz)

Neutron energy ↔ wavelength

Uses the non-relativistic neutron de Broglie relation E = 81.81 / λ², with E in meV and λ in Å, v = h / (mλ), and k = 2π / λ.

Energy (meV)

Wavelength (Å)

Wavevector (Å⁻¹)

Velocity (m/s)

Neutron momentum transfer

Converts between real-space distance and momentum transfer using Q = 2π / d. If the neutron wavelength above is set, it also converts to scattering angle using Q = 4π sin(θ) / λ.

Distance d (Å)

Q (Å⁻¹)

2θ (deg)

Edit any field within a converter; matching fields update automatically. The general converter accepts SI prefixes such as meV, km, nm, kHz, MHz, and GHz. Frequency outputs use prefixes up to THz through 10¹⁵ Hz, then switch to scientific notation.

← Back to tools