Theoretical analysis of the isostructural transition in Zr at 53 GPa

Recent diamond anvil x‐ray diffraction measurements in Zr show a first order isostructural transition at 53 GPa. (V/Vo=0.68), in addition to the known hcp to ω and ω to bcc transitions at 6.7 GPa and 33 GPa respectively. This transition has been attributed to the completion of s → d electron transfer in Zr. Here we have performed ab initio band structure calculations to analyze this transition. Our two panel LMTO calculations (that also include the 4p core states) rule out the completion of s → d electron transfer upto V/Vo=0.55. Although the 4p core levels broaden to about 315 mRyd, these also do not cause any discontinuity in the calculated isotherm. This suggests that further experimental work is needed to check the reported transition.

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