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 -7.916449063987 -0.69 4.9 146ms
2 -7.921204668594 -2.32 -1.51 1.0 57.2ms
3 -7.921402792775 -3.70 -2.49 1.2 60.5ms
4 -7.921440938442 -4.42 -2.82 2.4 78.1ms
5 -7.921441601908 -6.18 -2.98 1.0 57.6ms
6 -7.921442007089 -6.39 -4.53 1.0 57.7ms
7 -7.921442021846 -7.83 -4.63 2.9 112ms
8 -7.921442022130 -9.55 -5.35 1.0 58.4ms
9 -7.921442022140 -11.02 -5.47 1.6 66.5ms
10 -7.921442022144 -11.43 -5.92 1.0 59.3ms
11 -7.921442022144 -12.43 -6.60 1.2 226ms
12 -7.921442022144 -13.43 -7.52 1.9 69.8ms
13 -7.921442022144 -14.75 -7.94 1.9 93.4ms
14 -7.921442022144 + -Inf -8.21 1.2 61.6ms
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 2.04s Non-interacting
1 0 1 0.31 52.4 14.2s
2 0 2 -0.52 47.0 1.35s
3 0 3 -2.40 41.8 1.21s
4 0 4 -4.46 29.8 965ms
5 0 5 -6.46 17.4 693ms
6 0 6 -8.91 4.0 411ms
7 1 1 -7.87 55.4 1.96s Restart
8 1 2 -9.03 5.5 442ms
72.7 1.78s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.59s Non-interacting
1 0 1 0.31 52.4 1.51s
2 0 2 -0.52 47.0 1.31s
3 0 3 -2.40 41.8 1.19s
4 0 4 -4.46 29.8 940ms
5 0 5 -6.46 17.4 686ms
6 0 6 -8.91 4.0 404ms
7 1 1 -7.87 55.4 2.50s Restart
8 1 2 -9.03 5.5 430ms
72.7 1.78s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.64s Non-interacting
1 0 1 0.31 52.4 1.55s
2 0 2 -0.52 47.0 1.34s
3 0 3 -2.40 41.8 1.23s
4 0 4 -4.46 29.8 968ms
5 0 5 -6.46 17.4 707ms
6 0 6 -8.91 4.0 415ms
7 1 1 -7.87 55.4 1.86s Restart
8 1 2 -9.03 5.5 438ms
72.8 1.79s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
73.0 1.64s Non-interacting
1 0 1 0.31 52.4 1.54s
2 0 2 -0.52 47.0 2.04s
3 0 3 -2.40 41.8 1.17s
4 0 4 -4.46 29.8 983ms
5 0 5 -6.46 17.4 704ms
6 0 6 -8.91 4.0 427ms
7 1 1 -7.86 55.4 1.86s Restart
8 1 2 -9.00 5.5 449ms
72.7 1.80s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.64s Non-interacting
1 0 1 0.31 52.4 1.53s
2 0 2 -0.52 47.0 1.33s
3 0 3 -2.40 41.8 1.22s
4 0 4 -4.46 29.8 962ms
5 0 5 -6.46 17.4 703ms
6 0 6 -8.91 4.0 409ms
7 1 1 -7.86 55.4 2.59s Restart
8 1 2 -9.00 5.5 410ms
72.7 1.69s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
72.9 1.63s Non-interacting
1 0 1 0.31 52.4 1.52s
2 0 2 -0.52 47.0 1.33s
3 0 3 -2.40 41.8 1.21s
4 0 4 -4.46 29.8 949ms
5 0 5 -6.46 17.4 694ms
6 0 6 -8.91 4.0 418ms
7 1 1 -7.86 55.4 1.82s Restart
8 1 2 -9.00 5.5 440ms
72.8 1.78s Final orbitals
115.402579 seconds (159.99 M allocations: 83.318 GiB, 8.23% gc time, 29.62% compilation time)
These are the final phonon frequencies:
phret_q0.frequencies6-element Vector{Float64}:
-0.0034981553593321983
-0.0029774511581928415
-0.0029774511580578185
0.004302230620866517
0.004302230621116968
0.004353201752854081