Database statistics:

A total of 3,826 entries, including 300+ Fe-based rare-earth-free magnets discovered through our adaptive genetic algorithm (AGA) searches, are registered in our database. Data statistics are summarized here.

Phase diagrams:

Binary phases: Fe-N (38 entries), Fe-S (45 entries), Fe-Si (47 entries), Co-N (183 entries), Zr-Co (42 entries), among others.
Ternary phases: Fe-Co-N (272 entries), Fe-Co-S (34 entries), Zr-Co-B (50 entries), Zr-Co-C (55 entries), Zr-Co-N (79 entries), among others.

Benchmark test:

Benchmark results are summarized here, where we compare theoretical and experimental values.
random selection: Co-Ni (8 entries found)
Displaying 8 entries out of 8 entries found.
Crystallographic data Sstructural stability [Footnotes] Magnetic properties [Footnotes, magnetic units] Methods References
Materials ID Formula Formula units per cell Atomic sites per cell Crystal system Space group [Number] Formation energy (eV/atom) Energy relative to convex hull (eV/atom) Structure search Averaged magnetic moment (μB/atom) Magnetic polarization, Js (T) Magnetic easy axis Magnetic anisotropy constants:
Ka-c, Kb-c, Kb-a, Kd-a (MJ/m3)		 Curie temperature, TC (K) Methods References
MMD-3335 Ni(C2N3)3 4 64 orthorhombic Cmcm [63] 0.523 . MP 0.18 0.13 . . . . . . DFT mp-1246012
MMD-3337 Ni(CN)2 4 20 orthorhombic Pnma [62] 0.586 . MP 0.00 0.00 . . . . . . DFT mp-1246305
MMD-3345 Ni4CN4 4 36 orthorhombic Pnma [62] 0.334 . MP 0.00 0.00 . . . . . . DFT mp-1246802
MMD-3348 Ni2(CN2)3 3 33 trigonal R32 [155] 0.627 . MP 0.21 0.26 . . . . . . DFT mp-1246940
MMD-3349 Ni(C4N3)2 2 30 orthorhombic Pmna [53] 0.421 . MP 0.00 0.00 . . . . . . DFT mp-1247167
MMD-3352 Ni2(CN2)3 6 66 trigonal R-3c [167] 0.352 . MP 0.18 0.20 . . . . . . DFT mp-1247308
MMD-3384 Ni(C2N3)2 2 22 orthorhombic Pnnm [58] 0.343 . MP 0.18 0.15 . . . . . . DFT mp-22405
MMD-3445 NiCN2 2 8 hexagonal P6_3/mmc [194] 0.304 . MP 0.13 0.15 . . . . . . DFT mp-567262
Footnotes:
  1. Formation energy:
    We perform DFT calculations to calculate the total enegies of all the structures. The formation energy is computed with respect to a linear combination of the total energies of reference elemental phases. When the formation energies are plotted as a function of chemical composition, a set of stable compounds forms a convex hull, which represents a boundary (theoretical lower limit) in a compositional phase diagram. Metastable compounds lie above the hull, and the energy relative to the hull (distance to the hull) is a useful quantity to examine the metastability of a new compound. The lower the formation energy above the convex hull, the more likely it is for the material to exist.
  2. Magnetic anisotropy constants:
    Magnetic anisotropy constant, Ka-c, is defined as Ka-c = Ea-Ec, where Ea and Ec are the total energies per volume for the magnetization oriented along the crystallographic a and c axes, respectively. Similarly, Kb-c and Kb-a are defined as Kb-c = Eb-Ec and Kb-a = Eb-Ea, respectively. For cubic crystal systems, magnetic anisotropy constant is calculated as Kd-a = Ed-Ea, where Ed is the total energy per volume for the magnetization oriented along the body-diagonal direction of the unit cell.
Collaborative PIs:
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