Fast determination of melting curves at high pressure

Determination of accurate melting curves of materials is an old problem. In the past twenty years, reliable results have been obtained with ab-initio molecular dynamics (AIMD). These simulations are usually based on molecular dynamics of the solid or the liquid (one phase approach), or the direct simulation of the solid-liquid interface (two phases approach) [1]. Unfortunately, AIMD can be very time consuming, and prevent applications on complex systems or heavy elements. Fast alternative methods are necessary, at least to give a starting point for more complex calculations.
The famous phenomelogical Lindeman [2] approach based on the comparison of the amplitude of thermal vibrations of atoms with the interatomic distance and proposed more than 100 years ago is still widely used [3]. We have tested its validity for several metals (Au, Al, Fe…) on a large pressure scale. We will also discussed applications on MgO and U in regard to our recent calculations of vibrational frequencies in temperature [4].

[1] J Bouchet, F Bottin, G Jomard, G Zérah, Phys. Rev. B 80, 094102 (2008)
[2] F. A. Lindemann, Physik. Zeitschr. 11, 609 (1910)
[3] D. V. Minakov, P. R. Levashov, Phys. Rev. B 92, 224102 (2015)
[4] J Bouchet, F Bottin, Phys. Rev. B 95 , 054113 (2017)