Phonon computations
This is a quick sketch how to run a simple phonon calculation using DFTK.
Practical phonon computations have only seen rudimentary testing as of now. As of now we do not yet recommend relying on this feature for production calculations. We appreciate any issues, bug reports or PRs.
First we run an SCF calculation.
using AtomsBuilder
using DFTK
using PseudoPotentialData
pseudopotentials = PseudoFamily("cp2k.nc.sr.lda.v0_1.semicore.gth")
model = model_DFT(bulk(:Si); pseudopotentials, functionals=LDA())
basis = PlaneWaveBasis(model; Ecut=10, kgrid=[4, 4, 4])
scfres = self_consistent_field(basis, tol=1e-8);
nothing # hiden Energy log10(ΔE) log10(Δρ) Diag Δtime
--- --------------- --------- --------- ---- ------
1 -7.916419745218 -0.69 5.0 169ms
2 -7.921203771765 -2.32 -1.52 1.0 57.4ms
3 -7.921403946230 -3.70 -2.49 1.2 60.5ms
4 -7.921440947470 -4.43 -2.82 2.4 77.2ms
5 -7.921441589860 -6.19 -2.97 1.1 58.9ms
6 -7.921442007108 -6.38 -4.52 1.0 56.5ms
7 -7.921442021665 -7.84 -4.54 2.8 84.6ms
8 -7.921442022123 -9.34 -5.26 1.0 81.4ms
9 -7.921442022143 -10.70 -5.87 1.6 64.3ms
10 -7.921442022144 -12.03 -6.08 1.8 67.6ms
11 -7.921442022144 -12.60 -7.13 1.0 58.4ms
12 -7.921442022144 -13.73 -7.17 2.6 80.2ms
13 -7.921442022144 -14.57 -7.50 1.0 58.4ms
14 -7.921442022144 + -14.75 -8.12 1.0 116ms
Next we compute the phonon modes at the q-point [1/4, 1/4, 1/4].
scfres = DFTK.unfold_bz(scfres)
phret_q0 = @time DFTK.phonon_modes(scfres; q=[0.25, 0.25, 0.25]);
nothing # hideIter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 2.18s Non-interacting
1 0 1 0.31 52.5 9.93s
2 0 2 -0.52 47.1 1.48s
3 0 3 -2.40 41.7 1.30s
4 0 4 -4.46 29.6 1.02s
5 0 5 -6.46 17.4 745ms
6 0 6 -8.91 4.0 452ms
7 1 1 -7.81 55.6 2.12s Restart
8 1 2 -8.81 5.5 487ms
72.7 2.64s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.71s Non-interacting
1 0 1 0.31 52.5 1.69s
2 0 2 -0.52 47.1 1.46s
3 0 3 -2.40 41.7 1.33s
4 0 4 -4.46 29.6 1.04s
5 0 5 -6.46 17.4 758ms
6 0 6 -8.91 4.0 443ms
7 1 1 -7.81 55.6 2.01s Restart
8 1 2 -8.81 5.5 482ms
72.7 1.82s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.66s Non-interacting
1 0 1 0.31 52.5 1.59s
2 0 2 -0.52 47.1 1.36s
3 0 3 -2.40 41.7 1.24s
4 0 4 -4.46 29.6 988ms
5 0 5 -6.46 17.4 720ms
6 0 6 -8.91 4.0 423ms
7 1 1 -7.81 55.6 1.97s Restart
8 1 2 -8.81 5.5 1.18s
72.7 1.74s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.71s Non-interacting
1 0 1 0.31 52.5 1.65s
2 0 2 -0.52 47.1 1.44s
3 0 3 -2.40 41.7 1.31s
4 0 4 -4.46 29.6 1.04s
5 0 5 -6.46 17.4 747ms
6 0 6 -8.91 4.0 447ms
7 1 1 -7.82 55.6 1.95s Restart
8 1 2 -8.82 5.5 473ms
72.6 1.86s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.69s Non-interacting
1 0 1 0.31 52.5 1.56s
2 0 2 -0.52 47.1 1.35s
3 0 3 -2.40 41.7 1.24s
4 0 4 -4.46 29.6 996ms
5 0 5 -6.46 17.4 713ms
6 0 6 -8.91 4.0 414ms
7 1 1 -7.82 55.6 1.94s Restart
8 1 2 -8.82 5.5 1.20s
72.7 1.71s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.70s Non-interacting
1 0 1 0.31 52.5 1.66s
2 0 2 -0.52 47.1 1.42s
3 0 3 -2.40 41.7 1.30s
4 0 4 -4.46 29.6 1.03s
5 0 5 -6.46 17.4 753ms
6 0 6 -8.91 4.0 437ms
7 1 1 -7.82 55.6 1.96s Restart
8 1 2 -8.82 5.5 490ms
72.7 1.83s Final orbitals
115.882178 seconds (151.06 M allocations: 82.592 GiB, 7.36% gc time, 27.50% compilation time)
These are the final phonon frequencies:
phret_q0.frequencies6-element Vector{Float64}:
-0.003498155357707393
-0.0029774511619171983
-0.002977451161135081
0.004302230639869209
0.004302230640348434
0.004353201768976597