material

Ca2Si
ID:

mp-2517
DOI:

10.17188/1200545

Tags: Dicalcium silicide Calcium silicide (2/1) Calcium silicide

Material Details

Final Magnetic Moment
0.000 μB

Calculated total magnetic moment for the unit cell within the magnetic ordering provided (see below). Typically accurate to the second digit.
Magnetic Ordering
Unknown
Formation Energy / Atom
-0.463 eV

Calculated formation energy from the elements normalized to per atom in the unit cell.

Energy Above Hull / Atom
0.000 eV

The energy of decomposition of this material into the set of most stable materials at this chemical composition, in eV/atom. Stability is tested against all potential chemical combinations that result in the material's composition. For example, a Co2O3 structure would be tested for decomposition against other Co2O3 structures, against Co and O2 mixtures, and against CoO and O2 mixtures.

Density
2.17 g/cm3

The calculated bulk crystalline density, typically underestimated due calculated cell volumes overestimated on average by 3% (+/- 6%)

Decomposes To
Stable
Band Gap
0.291 eV

In general, band gaps computed with common exchange-correlation functionals such as the LDA and GGA are severely underestimated. Typically the disagreement is reported to be ~50% in the literature. Some internal testing by the Materials Project supports these statements; typically, we find that band gaps are underestimated by ~40%. We additionally find that several known insulators are predicted to be metallic.

Space Group

Hermann Mauguin
Pnma [62]
Hall
-P 2ac 2n
Point Group
mmm
Crystal System
orthorhombic

Band Structure

Density of States
Warning! Semi-local DFT tends to severely underestimate bandgaps. Please see the wiki for more info.

sign indicates spin ↑ ↓

  • Cu
  • Ag
  • Mo
  • Fe

Calculated powder diffraction pattern; note that peak spacings may be affected due to inaccuracies in calculated cell volume, which is typically overestimated on average by 3% (+/- 6%)

X-Ray Absorption Spectra

FEFF XANES

Select an element to display a spectrum averaged over all sites of that element in the structure.

Apply Gaussian smoothing:

0 eV
3 eV
FWHM: 0 eV

Download spectra for every symmetrically equivalent absorption site in the structure.

Download FEFF Input parameters.

Warning: These results are intended to be semi-quantitative in that corrections, such as edge shifts and Debye-Waller damping, have not been included.

Substrates

Reference for minimal coincident interface area (MCIA) and elastic energy:
substrate orientation:
substrate material substrate orientation film orientation elastic energy [meV] MCIA† [Å2]
CdWO4 (mp-19387) <0 0 1> <1 0 0> 0.001 275.6
MgO (mp-1265) <1 0 0> <1 1 0> 0.003 163.1
Al (mp-134) <1 0 0> <1 1 0> 0.003 81.5
KCl (mp-23193) <1 0 0> <1 1 0> 0.007 81.5
KTaO3 (mp-3614) <1 0 0> <1 1 0> 0.008 81.5
KCl (mp-23193) <1 1 0> <0 1 0> 0.015 174.4
LiTaO3 (mp-3666) <1 1 1> <0 0 1> 0.018 256.9
Ga2O3 (mp-886) <0 1 0> <0 1 1> 0.018 285.0
NaCl (mp-22862) <1 0 0> <1 1 0> 0.021 163.1
Cu (mp-30) <1 1 0> <1 0 0> 0.023 275.6
LiGaO2 (mp-5854) <0 1 0> <0 0 1> 0.026 293.6
NdGaO3 (mp-3196) <0 1 1> <0 1 0> 0.031 261.6
AlN (mp-661) <1 1 1> <0 0 1> 0.033 256.9
BaTiO3 (mp-5986) <1 0 0> <0 1 0> 0.042 305.2
TiO2 (mp-390) <1 1 0> <0 1 0> 0.051 261.6
ZnSe (mp-1190) <1 0 0> <1 1 0> 0.051 163.1
Ag (mp-124) <1 1 0> <1 1 1> 0.052 268.2
LiNbO3 (mp-3731) <1 1 1> <0 0 1> 0.057 256.9
SiC (mp-8062) <1 1 1> <0 0 1> 0.064 330.3
YAlO3 (mp-3792) <1 0 1> <1 1 0> 0.065 244.6
Cu (mp-30) <1 0 0> <1 0 0> 0.067 275.6
InP (mp-20351) <1 0 0> <0 1 1> 0.067 285.0
AlN (mp-661) <1 0 1> <0 1 0> 0.068 305.2
Mg (mp-153) <0 0 1> <0 0 1> 0.074 293.6
Au (mp-81) <1 1 0> <1 1 1> 0.077 268.2
GaAs (mp-2534) <1 0 0> <1 1 0> 0.079 163.1
BN (mp-984) <1 1 0> <1 0 1> 0.079 234.2
BaTiO3 (mp-5986) <0 0 1> <1 1 1> 0.102 178.8
Al2O3 (mp-1143) <1 0 1> <0 1 0> 0.103 130.8
BaTiO3 (mp-5986) <1 1 0> <0 1 0> 0.104 218.0
CdWO4 (mp-19387) <1 1 1> <0 1 0> 0.106 261.6
PbS (mp-21276) <1 0 0> <0 1 1> 0.108 285.0
BaTiO3 (mp-5986) <1 1 1> <1 0 1> 0.118 234.2
LiGaO2 (mp-5854) <1 1 0> <0 0 1> 0.128 146.8
C (mp-48) <1 0 1> <0 0 1> 0.129 220.2
Al2O3 (mp-1143) <1 0 0> <0 0 1> 0.130 256.9
SiC (mp-11714) <1 0 0> <1 0 1> 0.131 156.1
Ge (mp-32) <1 0 0> <1 1 0> 0.136 163.1
C (mp-66) <1 0 0> <0 0 1> 0.138 293.6
Si (mp-149) <1 1 1> <1 0 0> 0.140 206.7
CeO2 (mp-20194) <1 1 1> <1 0 0> 0.140 206.7
Al2O3 (mp-1143) <0 0 1> <0 1 1> 0.140 285.0
ZnO (mp-2133) <0 0 1> <0 1 1> 0.148 342.0
GaN (mp-804) <1 0 1> <0 1 0> 0.148 174.4
Te2Mo (mp-602) <1 0 0> <1 0 0> 0.149 275.6
CeO2 (mp-20194) <1 0 0> <1 0 1> 0.156 234.2
Bi2Te3 (mp-34202) <0 0 1> <1 0 0> 0.158 68.9
Si (mp-149) <1 0 0> <1 0 1> 0.162 234.2
TiO2 (mp-390) <1 0 0> <0 1 0> 0.164 261.6
C (mp-48) <0 0 1> <0 1 0> 0.171 218.0
Up to 50 entries displayed.
†minimal coincident interface area.

Elasticity

Reference for tensor and properties:
Visualize with ELATE
Stiffness Tensor Cij (GPa)
50 20 23 0 0 0
20 71 31 0 0 0
23 31 71 0 0 0
0 0 0 21 0 0
0 0 0 0 33 0
0 0 0 0 0 20
Compliance Tensor Sij (10-12Pa-1)
24.3 -4.1 -6.1 0 0 0
-4.1 18.2 -6.7 0 0 0
-6.1 -6.7 19 0 0 0
0 0 0 48.6 0 0
0 0 0 0 30.3 0
0 0 0 0 0 50.7
Shear Modulus GV
23 GPa
Bulk Modulus KV
38 GPa
Shear Modulus GR
21 GPa
Bulk Modulus KR
36 GPa
Shear Modulus GVRH
22 GPa
Bulk Modulus KVRH
37 GPa
Elastic Anisotropy
0.32
Poisson's Ratio
0.25

Dielectric Properties

Reference for tensor and properties: Methodology
Dielectric Tensor εij∞ (electronic contribution)
16.02 -0.00 0.00
0.00 16.24 -0.01
-0.00 0.01 15.03
Dielectric Tensor εij (total)
30.13 0.00 -0.00
0.00 30.96 -0.02
-0.00 -0.00 27.16
Polycrystalline dielectric constant εpoly∞
(electronic contribution)
15.76
Polycrystalline dielectric constant εpoly
(total)
29.42
Refractive Index n
3.97
Potentially ferroelectric?
False

Similar Structures

Explanation of dissimilarity measure: Documentation.
material dissimilarity Ehull # of elements
KNa4SnSb3 (mp-6758) 0.6246 0.004 4
Sr2Pb (mp-30828) 0.1069 0.000 2
Yb2Ge (mp-1694) 0.1298 0.000 2
Ca2Ge (mp-304) 0.0161 0.000 2
Sr2Si (mp-1106) 0.1434 0.000 2
Sr2Sn (mp-978) 0.1124 0.000 2
VAsRh (mp-20395) 0.2961 0.002 3
MoPRu (mp-22451) 0.3618 0.000 3
SrCaPb (mp-21166) 0.3340 0.000 3
KRbS (mp-28760) 0.2924 0.008 3
SrCaSn (mp-20726) 0.3348 0.000 3
Up to 5 similar elemental, binary, ternary, quaternary, etc. structures displayed (dissimilarity threshold 0.75). Ehull: energy above hull per atom [eV].

Calculation Summary

Elasticity

Methodology

Structure Optimization

Run Type
GGA
Energy Cutoff
520 eV
# of K-points
16
U Values
--
Pseudopotentials
VASP PAW: Si Ca_sv
Final Energy/Atom
-3.6044 eV
Corrected Energy
-43.2524 eV
-43.2524 eV = -43.2524 eV (uncorrected energy)

Detailed input parameters and outputs for all calculations

Show JSON History Show BibTex Citation Download BibTex Citation
ICSD IDs
  • 158275
  • 42453
  • 25595
Submitted by

Displaying lattice parameters for primitive cell; note that calculated cell volumes are typically overestimated on average by 3% (+/- 6%). Note the primitive cell may appear less symmetric than the conventional cell representation (see "Structure Type" selector below the 3d structure)