تقرير
Fundamental high pressure calibration from all-electron quantum Monte Carlo calculations
| العنوان: | Fundamental high pressure calibration from all-electron quantum Monte Carlo calculations |
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| المؤلفون: | Esler, K. P., Cohen, R. E., Militzer, B., Kim, Jeongnim, Needs, R. J., Towler, M. D. |
| سنة النشر: | 2010 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Materials Science |
| الوصف: | We develop an all-electron quantum Monte Carlo (QMC) method for solids that does not rely on pseudopotentials, and use it to construct a primary ultra-high pressure calibration based the equation of state of cubic boron nitride(c-BN). We compute the static contribution to the free energy with QMC, and obtain the phonon contribution from density functional theory, yielding a high-accuracy calibration up to 900 GPa usable directly in experiment. Furthermore, we compute the anharmonic Raman frequency shift with QMC as a function of pressure and temperature, allowing optical pressure calibration in table-top experiments. In contrast to present experimental approaches, small systematic errors in the theoretical EOS do not increase with pressure, and no extrapolation is needed. This all-electron methodology is generally applicable to first-row solids, and can be used to provide a new reference for ab initio calculations of solids and to benchmark pseudopotential accuracy. Comment: 4 pages, 2 figures, 1 table |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevLett.104.185702 |
| URL الوصول: | http://arxiv.org/abs/1001.2079 |
| رقم الأكسشن: | edsarx.1001.2079 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevLett.104.185702 |
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