Sr7CaTi8O20
High-Entropy Materials HEAMP-ID: mp-1076695 · Space group: P1 (#1)
Basic Information
Formula
Sr7CaTi8O20
MP-ID
mp-1076695
Elements
4
Sites
144
Density
4.5342
g/cm³
Volume
1,986.93
ų
Cell a
11.2575
Å
Cell b
11.2326
Å
Cell c
17.6256
Å
α Angle
108.55
°
β Angle
108.79
°
γ Angle
90.06
°
Space Group
P1
Point Group
1
Crystal System
Triclinic
Bravais Lattice
aP
Stability
No
Packing Fraction
-
X-ray Diffraction
Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 5.62 | 15.7131 | 9.9 | (0,0,1) |
| 11.26 | 7.8566 | 24.7 | (0,0,2) |
| 16.76 | 5.2889 | 1.9 | (0,2,0) |
| 16.76 | 5.2883 | 4.1 | (0,2,-2) |
| 22.35 | 3.9779 | 5.1 | (2,-2,0) |
| 22.37 | 3.9735 | 4.8 | (2,2,-2) |
| 22.64 | 3.9283 | 8.0 | (0,0,4) |
| 23.08 | 3.8539 | 1.0 | (2,-2,1) |
| 23.22 | 3.8308 | 2.3 | (0,2,2) |
| 23.22 | 3.8302 | 3.8 | (0,2,-4) |
| 25.07 | 3.5527 | 1.1 | (2,-2,-2) |
| 25.09 | 3.5492 | 1.3 | (2,2,-4) |
| 25.12 | 3.5452 | 1.9 | (2,-2,2) |
| 25.14 | 3.5424 | 1.7 | (2,2,0) |
| 28.40 | 3.1426 | 1.2 | (0,0,5) |
| 31.80 | 2.8144 | 100.0 | (4,0,-2) |
| 31.87 | 2.8081 | 94.3 | (0,4,-2) |
| 31.98 | 2.7988 | 79.6 | (2,-2,-4) |
| 32.00 | 2.7969 | 79.6 | (2,2,-6) |
| 32.06 | 2.7914 | 78.3 | (2,-2,4) |
| 32.08 | 2.7902 | 79.4 | (2,2,2) |
| 32.65 | 2.7427 | 2.9 | (0,2,4) |
| 32.65 | 2.7423 | 1.7 | (0,2,-6) |
| 34.24 | 2.6189 | 1.6 | (0,0,6) |
Energy Properties
Formation Energy/atom
-3.26542
eV/atom
Energy/atom
-8.15364
eV/atom
Energy above Hull
0.0713
eV/atom
Uncorrected Energy
-7.7720
eV/atom
Volume/atom
13.80
ų
c/a Ratio
1.5657
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
9.6444
μB
Mag. Ordering
FM
Mag. Sites
25
Magnetization/Volume
0.004850
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
O · 0.556
Element Family
Metalloid-Nonmetal
Solute Fraction
0.444
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
1.0788
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.9688
J/mol·K
Ω Parameter
0.0635
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
53.440%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
1.1064
smaller = more stable mixing
VEC
3.556
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-98.435
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7782
SS Former
0
Phase Tendency
AM
Related Tasks
Related computation task IDs (1)
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-1076695
Reference Citation
The crystal structure and related material properties of Sr7CaTi8O20 were obtained from the Materials Project database (MP-ID: mp-1076695, database version v2026.04.13).
Literature Citation
Horton, M.K., Huck, P., Yang, R.X. et al. Accelerated data-driven materials science with the Materials Project. Nat. Mater. 24, 1522–1532 (2025). https://doi.org/10.1038/s41563-025-02272-0
3D Crystal Structure Rendering
Loading 3D structure…
Style: Ball & Stick
|
Drag to rotate · Scroll to zoom · Right-click to pan
Raw CIF Data
# generated using pymatgen
data_Sr7CaTi8O20
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 11.25748435
_cell_length_b 11.23257187
_cell_length_c 17.62558528
_cell_angle_alpha 108.55023436
_cell_angle_beta 108.79457358
_cell_angle_gamma 90.06439020
_symmetry_Int_Tables_number 1
_chemical_formula_structural Sr7CaTi8O20
_chemical_formula_sum 'Sr28 Ca4 Ti32 O80'
_cell_volume 1986.92846571
_cell_formula_units_Z 4
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
1 'x, y, z'
loop_
_atom_site_type_symbol
_atom_site_label
_atom_site_symmetry_multiplicity
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Sr Sr0 1 0.30740200 0.05948600 0.61983200 1.0
Sr Sr1 1 0.30586500 0.55878900 0.61905800 1.0
Sr Sr2 1 0.80695600 0.05754200 0.61824500 1.0
Sr Sr3 1 0.80475700 0.56334200 0.11685300 1.0
Sr Sr4 1 0.80640100 0.55938200 0.61913200 1.0
Sr Sr5 1 0.18955800 0.43921500 0.38478100 1.0
Sr Sr6 1 0.18635300 0.44052900 0.88045100 1.0
Sr Sr7 1 0.19235500 0.93998400 0.38789600 1.0
Sr Sr8 1 0.18703400 0.94042300 0.87957900 1.0
Sr Sr9 1 0.69170600 0.44064500 0.38690900 1.0
Sr Sr10 1 0.68864100 0.44068800 0.88236800 1.0
Sr Sr11 1 0.68867000 0.93698600 0.38476900 1.0
Sr Sr12 1 0.68837700 0.93949200 0.88042600 1.0
Sr Sr13 1 0.05904200 0.30396700 0.11645900 1.0
Sr Sr14 1 0.05565900 0.30936600 0.61896000 1.0
Sr Sr15 1 0.05570400 0.80888300 0.61785100 1.0
Sr Sr16 1 0.55816400 0.30328300 0.11327700 1.0
Sr Sr17 1 0.55617400 0.31062700 0.62049800 1.0
Sr Sr18 1 0.55739600 0.80253000 0.11533100 1.0
Sr Sr19 1 0.55681300 0.80893700 0.61894500 1.0
Sr Sr20 1 0.44336200 0.19732300 0.38827700 1.0
Sr Sr21 1 0.43762600 0.18898000 0.88103400 1.0
Sr Sr22 1 0.43933300 0.69855900 0.38545800 1.0
Sr Sr23 1 0.43797900 0.68996700 0.88147800 1.0
Sr Sr24 1 0.93771200 0.19259100 0.38539000 1.0
Sr Sr25 1 0.93799600 0.18934100 0.88218000 1.0
Sr Sr26 1 0.93927100 0.69590600 0.38326300 1.0
Sr Sr27 1 0.93576200 0.68773000 0.87965900 1.0
Ca Ca28 1 0.30475000 0.05973500 0.10274600 1.0
Ca Ca29 1 0.30809500 0.56337900 0.10491100 1.0
Ca Ca30 1 0.80079300 0.05782900 0.10493500 1.0
Ca Ca31 1 0.05933300 0.79113100 0.10433400 1.0
Ti Ti32 1 0.00124400 0.99853100 0.00192000 1.0
Ti Ti33 1 0.99810000 0.00072500 0.50028300 1.0
Ti Ti34 1 0.99958800 0.49933900 0.00134800 1.0
Ti Ti35 1 0.99741500 0.49949600 0.49985800 1.0
Ti Ti36 1 0.49961100 0.99881600 0.99990600 1.0
Ti Ti37 1 0.49857700 0.00228700 0.50175000 1.0
Ti Ti38 1 0.49860800 0.49813400 0.99989900 1.0
Ti Ti39 1 0.49774800 0.50133300 0.50110200 1.0
Ti Ti40 1 0.24891500 0.25104700 0.99967300 1.0
Ti Ti41 1 0.24809200 0.24952400 0.50147100 1.0
Ti Ti42 1 0.24863900 0.75082500 0.99940100 1.0
Ti Ti43 1 0.24777000 0.74938300 0.50048900 1.0
Ti Ti44 1 0.74987300 0.24899600 0.99973800 1.0
Ti Ti45 1 0.74693000 0.24952700 0.50135100 1.0
Ti Ti46 1 0.75085500 0.75169500 0.00166600 1.0
Ti Ti47 1 0.74696500 0.74852300 0.49999000 1.0
Ti Ti48 1 0.10714400 0.09659700 0.24554800 1.0
Ti Ti49 1 0.11669900 0.11765500 0.75077600 1.0
Ti Ti50 1 0.11583500 0.61234800 0.24858700 1.0
Ti Ti51 1 0.12471300 0.61733900 0.75019200 1.0
Ti Ti52 1 0.60751400 0.11313100 0.24815300 1.0
Ti Ti53 1 0.61827800 0.11702300 0.75111400 1.0
Ti Ti54 1 0.61234300 0.61400500 0.24833400 1.0
Ti Ti55 1 0.62553900 0.61713900 0.75122700 1.0
Ti Ti56 1 0.36916800 0.39654000 0.24743500 1.0
Ti Ti57 1 0.37516000 0.38415200 0.75150000 1.0
Ti Ti58 1 0.35881800 0.89234200 0.24590200 1.0
Ti Ti59 1 0.36649800 0.88341600 0.75075700 1.0
Ti Ti60 1 0.86481800 0.38663400 0.24886800 1.0
Ti Ti61 1 0.87545000 0.38281800 0.75122000 1.0
Ti Ti62 1 0.85916200 0.89241200 0.24821200 1.0
Ti Ti63 1 0.86773800 0.88298900 0.75119800 1.0
O O64 1 0.12105600 0.12332500 0.49674700 1.0
O O65 1 0.12145200 0.12064900 0.99292800 1.0
O O66 1 0.11902000 0.62038800 0.49256800 1.0
O O67 1 0.12021300 0.62206900 0.99380200 1.0
O O68 1 0.62004600 0.12275100 0.49585900 1.0
O O69 1 0.62067900 0.11984300 0.99211000 1.0
O O70 1 0.62077300 0.62323800 0.49761500 1.0
O O71 1 0.61990000 0.62095700 0.99250700 1.0
O O72 1 0.13391800 0.38444500 0.01446600 1.0
O O73 1 0.12462600 0.37625000 0.50405800 1.0
O O74 1 0.13243100 0.88148400 0.01374800 1.0
O O75 1 0.12536900 0.87753100 0.50633900 1.0
O O76 1 0.62897100 0.37789300 0.00843800 1.0
O O77 1 0.62531300 0.37878800 0.50741400 1.0
O O78 1 0.63201300 0.88243200 0.01024500 1.0
O O79 1 0.62445300 0.87737200 0.50489500 1.0
O O80 1 0.37105400 0.12399700 0.49685600 1.0
O O81 1 0.37009600 0.12075600 0.99386600 1.0
O O82 1 0.36858400 0.62123000 0.49216500 1.0
O O83 1 0.36845800 0.62003200 0.99265200 1.0
O O84 1 0.86832400 0.12125000 0.49299100 1.0
O O85 1 0.87154700 0.11892900 0.99604300 1.0
O O86 1 0.86891800 0.62074800 0.49216400 1.0
O O87 1 0.87234300 0.62338500 0.99497100 1.0
O O88 1 0.37820300 0.38069000 0.01206500 1.0
O O89 1 0.37259600 0.37605000 0.50163300 1.0
O O90 1 0.37884500 0.88124300 0.01212400 1.0
O O91 1 0.37533100 0.87815400 0.50520500 1.0
O O92 1 0.88125000 0.37957200 0.01281500 1.0
O O93 1 0.87387800 0.37644200 0.50473100 1.0
O O94 1 0.88472000 0.88180500 0.01696300 1.0
O O95 1 0.87260300 0.87475900 0.50026400 1.0
O O96 1 0.07581600 0.09006200 0.13266500 1.0
O O97 1 0.05796500 0.07584400 0.62900500 1.0
O O98 1 0.06533400 0.59464600 0.13170000 1.0
O O99 1 0.05911200 0.57763800 0.62862100 1.0
O O100 1 0.56426800 0.08599800 0.12957200 1.0
O O101 1 0.56272900 0.07738900 0.62978400 1.0
O O102 1 0.56037900 0.58057000 0.12749100 1.0
O O103 1 0.55635900 0.57673000 0.62948000 1.0
O O104 1 0.43783200 0.41955100 0.36602700 1.0
O O105 1 0.42967800 0.41503500 0.87227800 1.0
O O106 1 0.42894400 0.92770100 0.36716400 1.0
O O107 1 0.43239900 0.91622700 0.87246400 1.0
O O108 1 0.93200500 0.41339400 0.36801800 1.0
O O109 1 0.93309200 0.41720500 0.87384000 1.0
O O110 1 0.93953600 0.92585600 0.36792300 1.0
O O111 1 0.93385800 0.91536700 0.87396000 1.0
O O112 1 0.31635700 0.28391900 0.13409000 1.0
O O113 1 0.31137100 0.30398300 0.62928800 1.0
O O114 1 0.31175300 0.78545200 0.13041400 1.0
O O115 1 0.31276700 0.80015200 0.62920800 1.0
O O116 1 0.81196300 0.28386100 0.13217700 1.0
O O117 1 0.81137300 0.29996700 0.62986600 1.0
O O118 1 0.80982700 0.79483600 0.13118100 1.0
O O119 1 0.81546700 0.80257900 0.62943300 1.0
O O120 1 0.18148400 0.18858500 0.36481700 1.0
O O121 1 0.18536800 0.20593400 0.87366400 1.0
O O122 1 0.18144100 0.70260200 0.36891800 1.0
O O123 1 0.18170000 0.70591100 0.87292100 1.0
O O124 1 0.67235600 0.19963700 0.36925200 1.0
O O125 1 0.68905800 0.20356800 0.87328400 1.0
O O126 1 0.67190400 0.69255500 0.36963100 1.0
O O127 1 0.68656300 0.70603300 0.87361800 1.0
O O128 1 0.44585500 0.03379100 0.23946300 1.0
O O129 1 0.49611500 0.00276300 0.75370100 1.0
O O130 1 0.45331700 0.53605300 0.23940300 1.0
O O131 1 0.49603200 0.50618300 0.75518800 1.0
O O132 1 0.94709200 0.03932800 0.23938400 1.0
O O133 1 0.99727100 0.00242600 0.75511800 1.0
O O134 1 0.97739300 0.51156300 0.24711100 1.0
O O135 1 0.99507800 0.50477100 0.75314600 1.0
O O136 1 0.22379100 0.47953400 0.25003400 1.0
O O137 1 0.24569900 0.50017200 0.75233800 1.0
O O138 1 0.19398500 0.95001400 0.24076500 1.0
O O139 1 0.24649600 0.00259700 0.75218100 1.0
O O140 1 0.72939900 0.48997900 0.24807800 1.0
O O141 1 0.74523600 0.49789000 0.75253700 1.0
O O142 1 0.71698400 0.98463300 0.25188500 1.0
O O143 1 0.74637400 0.99977300 0.75251700 1.0
