# Unravelling Guest Dynamics in Crystalline Molecular Organics Using 2H Solid-State NMR and Molecular Dynamics Simulation

## TL;DR

This paper uses NMR and simulations to study how guest molecules move in crystalline organic structures.

## Contribution

A novel approach combining 2H solid-state NMR and MD simulations to accurately interpret molecular dynamics in cocrystal solvates.

## Key findings

- Traditional NMR interpretation methods fail to capture accurate molecular behavior in cocrystal solvates.
- MD simulations reveal jump-type and libration-type motions that align with NMR data.
- Time-independent component analysis provides insights into motions undetectable by NMR.

## Abstract

2H solid-state NMR and atomistic molecular
dynamics
(MD) simulations are used to understand the disorder of guest solvent
molecules in two cocrystal solvates of the pharmaceutical furosemide.
Traditional approaches to interpreting the NMR data fail to provide
a coherent model of molecular behavior and indeed give misleading
kinetic data. In contrast, the direct prediction of the NMR properties
from MD simulation trajectories allows the NMR data to be correctly
interpreted in terms of combined jump-type and libration-type motions.
Time-independent component analysis of the MD trajectories provides
additional insights, particularly for motions that are invisible to
NMR. This allows a coherent picture of the dynamics of molecules restricted
in molecular-sized cavities to be determined.