Table 3. Free energy difference between Y and W polymorphs and its decomposition into contributions obtained at 300 K from different models. All values are in kJ mol⁻¹ .

300 K	Γ	Supercell	NKA	NKA anharmonic	mta-NoMoRe_AO	mta-NoMoRe_FG
ΔG total (Y−W/2) (kJ mol−1)	4.36	−0.03	0.65	−0.65*	−1.76*	−3.04*
ΔE electronic (Y−W/2) (kJ mol−1)	−3.25	−4.30	−3.25*	−3.25*	−3.25*	−3.25*
ΔST (Y−W/2) (kJ mol−1)	−10.96	−2.99	−3.50	−2.17	−1.11	0.50
ΔZPE (Y−W/2) (kJ mol−1)	1.15	2.72	1.79	1.72	1.50	1.90
ΔH vib (Y−W/2) (kJ mol−1)	−4.49	−1.43	−1.39	−1.32	−1.12	−1.19
Estimated phase transition temp. (K)	130	300	260	380	600	2000