  Predictions of the anisotropic coefficients of thermal expansion are needed
to not only compare to experimental measurement, but also as input for
macroscopic modeling of devices which operate over a large temperature range.
While most current methods are limited to isotropic systems within the
quasiharmonic approximation, our method uses first-principles calculations and
includes anharmonic effects to determine the temperature-dependent properties
of materials. These include the lattice parameters, anisotropic coefficients of
thermal expansion, isothermal bulk modulus, and specific heat at constant
pressure. Our method has been tested on two compounds (Cu and AlN) and predicts
thermal properties which compare favorably to experimental measurement over a
wide temperature range.
