Open AccessLattice dynamics and thermal crystallographic parameters in phenothiazine
Author(s) -
Criado A.,
Conde A.,
Márquez R.
Publication year - 1984
Publication title -
acta crystallographica section a
Language(s) - English
Resource type - Journals
eISSN - 1600-5724
pISSN - 0108-7673
DOI - 10.1107/s0108767384001422
Subject(s) - lattice (music) , monoclinic crystal system , phenothiazine , formalism (music) , thermal , physics , crystal system , crystal structure , distribution function , statistical physics , condensed matter physics , thermodynamics , quantum mechanics , crystallography , chemistry , medicine , art , musical , visual arts , acoustics , pharmacology
A computer program has been developed to study the lattice dynamics of molecular crystals in the harmonic approximation with the external Born-von Karman formalism and an atom-atom potential function. Dispersion curves are obtained for monoclinic phenothiazine together with frequency distribution functions and external mode contribution to thermodynamic functions. Lattice dynamical T, L and S rigid-body tensors are obtained and individual thermal tensors are compared with experiment. The disagreement with respect to experimental results is of the same order as the disagreement with a Schomaker-Trueblood fit of experimental data.