Calculation of Diamagnetic Susceptibility Tensors of Organic Crystals: From Coronene to Pharmaceutical Polymorphs.
J Phys Chem A
; 124(7): 1409-1420, 2020 Feb 20.
Article
in En
| MEDLINE
| ID: mdl-31951408
ABSTRACT
Understanding why crystallization in strong magnetic fields can lead to new polymorphs requires methods to calculate the diamagnetic response of organic molecular crystals. We develop the calculation of the macroscopic diamagnetic susceptibility tensor, χcryst, for organic molecular crystals using periodic density functional methods. The crystal magnetic susceptibility tensor, χcryst, for all experimentally known polymorphs, and its molecular counterpart, χmol, are calculated for flexible pharmaceuticals such as carbamazepine, flufenamic acid, and chalcones, and rigid molecules, such as benzene, pyridine, acridine, anthracene, and coronene, whose molecular magnetic properties have been traditionally studied. A tensor addition method is developed to approximate the crystal diamagnetic susceptibility tensor, χcryst, from the molecular one, χmol, giving good agreement with those calculated directly using the more costly periodic density functional method for χcryst. The response of pharmaceutical molecules and crystals to magnetic fields, as embodied by χcryst, is largely determined by the packing in the crystal, as well as the molecular conformation. The anisotropy of χcryst can vary considerably between polymorphs though the isotropic terms are fairly constant. The implications for developing a computational method for predicting whether crystallization in a magnetic field could produce a novel or different polymorph are discussed.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polycyclic Compounds
/
Polymers
/
Pharmaceutical Preparations
/
Density Functional Theory
Language:
En
Journal:
J Phys Chem A
Journal subject:
QUIMICA
Year:
2020
Type:
Article
Affiliation country:
United kingdom