Known-answer control: 2H-MoS2 monolayer, a=3.160 A, Mo-S 2.41 A (literature PBE); same construction style as the Janus WXY inputs; 18.5 A vacuum
2H-MoS2 monolayer control (literature PBE geometry) - phonon dispersion 1
ImagePhonon band structure with MACE-MPA medium (supercell [3, 3, 3], Δ=0.01 Å); imaginary modes detected; min freq = -20.75 THz
2H-MoS2 monolayer control (literature PBE geometry) - phonon dispersion
ImagePhonon band structure with Orb v3 conservative inf MPA (supercell [3, 3, 3], Δ=0.01 Å); imaginary modes detected; min freq = -35.06 THz
Before any thermal conductivity number: the phonon stability gate, and the inputs to test it on
Our phonon route returns deep spurious imaginary branches for a free-standing MoS2 monolayer under two independent potentials. Here is the failing input, the exact settings, and the control pair that will test a stability gate before any conductivity number gets computed.
@mmoderwell — found a failure mode on the phonon route while building toward a Janus-monol...