Automated workflow for accurate scattering function calculation of light water using quantum corrections

Accurate calculation of the neutron scattering function for light water from theoretical model is often limited due to the challenges associated with the incoherent and inelastic correction of hydrogen. Traditional correction methods rely on empirical formulas, which lack generality and accuracy. Although quantum correction methods for light water have been studied for a while, they have not yet been translated into practical, openly available tools for calculating the scattering function <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mi>S</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>Q</mml:mi> <mml:mo>,</mml:mo> <mml:mi>ω</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:math> . In this paper, we present an open-source computational tool that provides a stable numerical implementation of the Gaussian approximation-assisted quantum correction (GAAQC) framework for light water. The tool applies quantum corrections to classical neutron scattering data derived from molecular dynamics (MD) simulations. It takes two inputs-both obtainable from standard MD trajectories: (a) the vibrational density of states (VDOS) and (b) the classical scattering function <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>S</mml:mi> <mml:mtext>cl</mml:mtext> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:mi>Q</mml:mi> <mml:mo>,</mml:mo> <mml:mi>ω</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:math> -and outputs the quantum-corrected scattering function <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mi>S</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>Q</mml:mi> <mml:mo>,</mml:mo> <mml:mi>ω</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:math> . Our implementation overcomes the instabilities that previously limited the GAAQC method, enabling reliable calculation over a wide dynamic range of momentum and energy transfer.