Equation of state for diamond in wide ranges of pressure and temperature

Theoretical total energy and phonon calculations for diamond under strong compressions up to 3 TPa are analyzed with different analytical forms for the representation of p-V isotherms. A simple model with only two characteristic (volume dependent) phonon parameters-an effect acoustic Debye temperature and an additional Einstein temperature of the optical phonons-provides a complete modeling of all the thermophysical properties of diamond in this extended range of pressure up to the melting curve. The comparison with thermophysical data at ambient pressure provides additional information oil weak intrinsic anharmonic contributions and gives the frame for the complete modeling up to 3 TPa in pressure and temperatures up to the melting curve. (c) 2008 American Institute of Physics.