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Electron correlation and the phase diagram of Si

D. Alfè·M. J. Gillan
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Abstract

Previous first-principles calculations of the melting properties of Si, based on the local-density approximation (LDA) for electronic exchange-correlation energy, under-predict the melting temperature by ~ 20%. We present new first-principles results demonstrating that this problem is due to non-cancellation of exchange-correlation errors between the semiconducting solid and the metallic liquid. It is shown that other sources of error, particularly those due to system size and Brillouin-zone sampling, can be made negligible. The same LDA errors cause an underprediction of the pressure of the diamond-Si --> beta-tin-Si transition. The generalized-gradient approximation largely corrects both features of the Si phase diagram.

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D. Alfè, M. J. Gillan. 2002-07-22. Electron correlation and the phase diagram of Si. https://doi.org/10.1103/physrevb.68.205212

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