2014 August

Quantum Effects in Classical Aspirin

Monday, 4th August 2014Miscellaneous

Aspirin is a widely used painkiller, but the relative stability of the abundant crystal structure of aspirin has been subject to many controversies during the last decade, especially after the discovery of the so-called form II of aspirin. Our paper demonstrates that the stability of the ubiquitous form I of aspirin found in aspirin pills is due to subtle coupling between quantum-mechanical atomic vibrations and electronic many-body interactions. The widespread nature of such quantum-mechanical interactions could have wider implications, ranging from the functionality of drugs to the texture and appearance of chocolate.

Role of Dispersion Interactions in the Polymorphiasm and Entropic Stabilization of the Aspirin Crystal
Anthony M. Reilly and Alexandre Tkatchenko
Physical Review Letters 113, 055701 (2014)/DOI: http://dx.doi.org/10.1103/PhysRevLett.113.055701

Link to highlighted paper synopsis: http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.113.055701

(Top) The unit-cell structures of form-I (left) and form-II (right) aspirin (acetylsalicylic acid). The b direction is perpendicular to a and c. (Bottom) View of form-I (left) and form-II (right) aspirin showing the different interlayer hydrogen-bonding motifs.