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Structural formula: Na

Force-field: Na_MendelevM_2014.eam.fs

Space group : P6_3/mmc

JARVIS ID: JLMP-1609

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Elastic tensor (GPa)

Elastic tensor for the conventional cell of the system were calculated with LAMMPS in.elastic script at 0 K [Source] . Similar script can be used for temperature dependent elastic constants and will be available here soon. WARNING! Please note that the starting lattice parameters of crystal structures were taken from density functional theory (DFT) and not from experiments. Generic minimization parameters were chosen for LAMMPS run rather than testing them for each individual case such as energy convergence criterion and so on. Hence, there are chances that the calculation gets trapped in a local energy minima. Please read carefully the assumptions taken during calculations in the in.elastic script and use the data at your own risk

-8.6 17.6 1.8 0.0 -0.0 3.9
17.6 -7.3 1.8 -0.0 -0.0 0.0
1.8 1.8 12.0 0.0 -0.0 0.0
0.0 -0.0 0.0 0.9 0.0 -0.0
-0.0 -0.0 -0.0 0.0 0.9 0.0
3.9 0.0 0.0 -0.0 0.0 -12.7

Bv: 4.3 GPa

Gv: -3.9 GPa

Vacancy-formation energy (eV)

Vacancy formation energies were calculated by deleting the symmterically distinct atoms in the system [Source]. In the table, vacancy forming element, its multiplicity, and defect-formation energy are given. The reference element cohesive energies were calculated with the most stable structure for the element found on materials project database. Defect structures were constructed with the fully-relaxed bulk system as input. For defect-structures energetics calculations, constant volume ensemble was used. We impose the defect structures to be at least 1.5 nm large in all directions.

Element Mult. Value
Na 2 0.267 Download cif file
Na 2 0.252 Download cif file

Surface energy (J/m2)

Surface energies were calculated for symmterically distinct crystal surfaces . In the table, (hkl) indices and surface enegies are given. For surface-structure energetics, constant volume ensemble was used. We impose the slab thickness to be at least 2 nm and vaccum size of 2.5 nm. The maximum miller index is taken as 3.

Surface Value
(2 2 1) 0.172 Download cif file
(0 0 1) 0.174 Download cif file
(3 3 1) 0.174 Download cif file
(1 0 2) 0.174 Download cif file
(2 -1 2) 0.175 Download cif file
(3 -1 0) 0.178 Download cif file
(3 2 0) 0.179 Download cif file
(1 1 1) 0.179 Download cif file
(1 0 3) 0.181 Download cif file
(3 -1 3) 0.183 Download cif file
(3 1 0) 0.185 Download cif file
(3 0 1) 0.187 Download cif file
(2 0 1) 0.188 Download cif file
(3 0 2) 0.191 Download cif file
(3 3 2) 0.191 Download cif file
(3 1 1) 0.195 Download cif file
(2 0 3) 0.196 Download cif file
(1 1 0) 0.196 Download cif file
(3 -1 1) 0.197 Download cif file
(3 -1 2) 0.197 Download cif file
(3 2 2) 0.198 Download cif file
(2 -1 3) 0.199 Download cif file
(1 0 1) 0.2 Download cif file
(3 1 2) 0.204 Download cif file
(3 1 3) 0.204 Download cif file
(3 2 1) 0.205 Download cif file
(1 0 0) 0.205 Download cif file
(3 2 3) 0.208 Download cif file
(2 2 3) 0.215 Download cif file

Phonon

Phonons were obtained by making an interface of JARVIS-FF with Phonopy package at 0 K [Source] . For deformed-structures, constant volume ensemble was used. The deofrmed structures were taken of at least 1.5 nm size in all directions. The band-indices for phonon bandstructure was obtained with Pymatgen. The phonon representation were obtained with phonopy. "I" and "R" denotes infrared and Raman active modes respectively

Visualize Phonons here
Phonon mode (cm-1) Representation
-0.0136941074 None
-0.0017225415 A2u I
-3.8848e-05 None
14.6795219388 None
14.7147248433 None
28.5656463706 E2u
32.4092200199 None
32.4229344699 None
80.1642956304 B2g
93.1516116026 B1u
127.900947661 A2u I
All phonon mode at Gamma point (cm-1)
-0.0136941073
-0.0017225415
-3.88404e-05
14.6795219388
14.7147248433
28.5656463706
28.5656464196
32.4092200199
32.4229344699
80.1642956304
93.1516116026
127.900947661

See also

Links to other databases or papers are provided below

JVASP-25398

mp-982370

Energy above hull from mp (eV): 0.0032732525