Structure, elastic moduli and thermodynamics of sodium and potassium at ultra-high pressures
arXiv:cond-mat/9912245 · doi:10.1103/PhysRevB.61.14420
Abstract
The equations of state at room temperature as well as the energies of crystal structures up to pressures exceeding 100 GPa are calculated for Na and K . It is shown that the allowance for generalized gradient corrections (GGA) in the density functional method provides a precision description of the equation of state for Na, which can be used for the calibration of pressure scale. It is established that the close-packed structures and BCC structure are not energetically advantageous at high enough compressions. Sharply non-monotonous pressure dependences of elastic moduli for Na and K are predicted and melting temperatures at high pressures are estimated from various melting criteria. The phase diagram of K is calculated and found to be in good agreement with experiment.
4 pages, 7 Postscript figures, Revtex, extended version, to appear in Phys. Rev. B
Cited by in corpus (5)
- Ab initio quality neural-network potential for sodium
- Structure stability in the simple element sodium under pressure
- Simple Metals at High Pressure
- Alkali-metal vibrations in bcc, fcc, hcp, and 9R structures: Implications for the energetics of Li and Na martensitic phases
- Comparative analysis for the behavior of beryllium and magnesium crystals at ultrahigh pressures