Table 1. Values of parameter used in the phase-field simulations (SI units and T in K).

Parameter	Value	Unit
a1	3.85(T−752)×105	C−2m2N
a11	−7.3×107	C−4m6N
a12	7.5×108	C−4m6N
a111	2.6×108	C−6m10N
a112	6.1×108	C−6m10N
a123	−3.7×109	C−6m10N
s11	8.0×10−12	m2N−1
s12	−2.5×10−12	m2N−1
s44	9.0×10−12	m2N−1
Q11	0.089	C−2m4
Q12	−0.026	C−2m4
Q44	0.0675	C−2m4
G11	3.46×10−10	m4NC−2
G12	0	m4NC−2
G44	1.73×10−10	m4NC−2
G′44	1.73×10−10	m4NC−2
DSi	3.46×10−10	m4NC−2
δieff	5×10−9	m
εb	4.425×10−10	Fm−1

Values of the expansion coefficients of the Landau potential, elastic compliance and electrostrictive coefficients are from ref. 42, the isotropic gradient coefficients are from ref. 47, the extrapolation length is from ref. 48, and the background dielectric constant is from ref.38 and 39.