The existence of a new high-pressure low-symmetry (HPLS) \(\hbox {ZrSiO}_4\) phase (space group \(I\bar{4}2d\)), which has been predicted by density-functional-theory (DFT) calculations (Stangarone et al. in Am Mineral, 2019b), is experimentally confirmed by in situ high-pressure Raman spectroscopic analysis up to 25.3 GPa. The new \(\hbox {ZrSiO}_4\) polymorph is developed from zircon via a soft-mode-driven displacive phase transition. The Cochran-law-type pressure dependency of the soft-mode wavenumber reveals a zircon-to-HPLS critical pressure \(p_{{\mathrm{c}}}\) = 20.98 ± 0.02 GPa. The increase in the phonon compressibilities of the zircon hard mode near \(\hbox {202 cm}^{-1}\) at \(p>p_{{\mathrm{r}}}=10.0\) GPa as well as of the reidite hard mode near \(\hbox {349 cm}^{-1}\) at \(p<p_{\mathrm {r}}\) marks the pressure above which zircon becomes thermodynamically metastable with respect to reidite; the experimentally determined value of \(p_{\mathrm {r}}\) is in good accordance with the equilibrium zircon–reidite transition pressure derived from DFT simulations. However, at room temperature, there is not enough driving force to rebuild the atomic linkages and the reconstructive transition to reidite happens \(\sim\) 1.4 GPa above \(p_{\mathrm {c}}\), indicating that at room temperature, the HPLS phase is a structural bridge between zircon and reidite. The pressure dependencies of the phonon modes in the range \(\hbox {350--460 cm}^{-1}\) reveal that the reconstructive phase transition in the \(\hbox {ZrSiO}_4\) system is triggered by energy resonance and admixture of hard modes from the parent and resultant phase.

存在新的高压低对称（HPLS）\（\ hbox {ZrSiO} _4 \）相（空间组\（I \ bar {4} 2d \）），该相已通过密度泛函-理论（DFT）计算（Stangarone等人，Am Mineral，2019b）通过高达25.3 GPa的原位高压拉曼光谱分析得到了实验证实。新的\（\ hbox {ZrSiO} _4 \）多晶型物是通过软模式驱动的位移相变从锆石中开发出来的。软模波数的Cochran律式压力相关性揭示了锆石到HPLS的临界压力\（p _ {{\ mathrm {c}}} \\） = 20.98±0.02 GPa。\（\ hbox {202 cm} ^ {-1} \）附近的锆石硬模的声子压缩率增加在\（p> p _ {{{mathrm {r}}} = 10.0 \） GPa以及\（\ hbox {349 cm} ^ {-1} \）在\（p <p_ {\ mathrm {r}} \）表示锆石相对于辉石的热力学亚稳态压力；实验确定的\（p _ {\ mathrm {r}} \）的值与DFT模拟得出的平衡锆石-白云石转变压力非常吻合。但是，在室温下，没有足够的驱动力来重建原子键，并且发生了向莱迪石的重构过渡，\（\ sim \）比\（p _ {\ mathrm {c}} \）高1.4 GPa 。，表明在室温下，HPLS相是锆石和辉石之间的结构桥。声子模式在\（\ hbox {350--460 cm} ^ {-1} \）范围内的压力依赖性揭示了\（\ hbox {ZrSiO} _4 \）系统中的重构相变是由以下因素触发的来自母相和合成相的能量共振和硬模的混合。