Approaching the strongly anharmonic limit with ab initio calculations of materials’ vibrational properties – a colloquium*

摘要: Despite ab initio computational techniques have opened new possibilities to interpret experimental results and predict the properties of materials, their applications are limited by adopted approximative schemes. Consequently, first-principles calculation many physical phenomena is hindered methods need be further developed overcome such limits. For example, standard harmonic approximation used assess vibrational materials often completely breaks down, so that calculated including strong anharmonic effects. The has also intrinsic failures as it cannot estimate lattice thermal conductivity nor temperature dependence phonon frequencies, crucial account for driven second-order phase transitions. Several in last years anharmonicity non-perturbative regime difficulties briefly reviewed this colloquium paper. In particular, stochastic self-consistent approximation, a variational method allows calculating strongly systems, described detail. Applications latter superconducting palladium, platinum, sulfur hydrides discussed, where huge impact on properties.