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 -7.916441726278 -0.69 4.8 115ms
2 -7.921210947970 -2.32 -1.52 1.0 58.6ms
3 -7.921405598457 -3.71 -2.49 1.4 60.1ms
4 -7.921440963664 -4.45 -2.82 2.6 80.8ms
5 -7.921441617604 -6.18 -2.99 1.0 59.8ms
6 -7.921442009293 -6.41 -4.53 1.0 60.4ms
7 -7.921442021738 -7.90 -4.56 2.8 91.0ms
8 -7.921442022126 -9.41 -5.34 1.0 64.4ms
9 -7.921442022143 -10.78 -5.97 1.9 70.1ms
10 -7.921442022144 -12.15 -6.11 1.8 66.3ms
11 -7.921442022144 -12.73 -6.71 1.0 221ms
12 -7.921442022144 -13.82 -7.10 1.8 64.7ms
13 -7.921442022144 -14.75 -7.54 1.4 61.5ms
14 -7.921442022144 -14.75 -8.03 1.2 109ms
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
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.97s Non-interacting
1 0 1 0.31 14.7 12.9s
2 0 2 -0.52 13.1 1.27s
3 0 3 -2.40 11.7 1.12s
4 0 4 -4.46 8.6 889ms
5 0 5 -6.46 5.1 632ms
6 0 6 -8.91 1.0 370ms
7 1 1 -7.81 16.5 1.88s Restart
8 1 2 -8.90 2.1 394ms
18.6 2.22s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.52s Non-interacting
1 0 1 0.31 14.7 1.44s
2 0 2 -0.52 13.1 1.24s
3 0 3 -2.40 11.7 1.13s
4 0 4 -4.46 8.6 884ms
5 0 5 -6.46 5.1 718ms
6 0 6 -8.91 1.0 1.02s
7 1 1 -7.81 16.5 1.57s Restart
8 1 2 -8.90 2.1 387ms
18.6 1.56s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.50s Non-interacting
1 0 1 0.31 14.7 1.44s
2 0 2 -0.52 13.1 1.25s
3 0 3 -2.40 11.7 1.12s
4 0 4 -4.46 8.6 891ms
5 0 5 -6.46 5.1 633ms
6 0 6 -8.91 1.0 365ms
7 1 1 -7.81 16.5 1.70s Restart
8 1 2 -8.90 2.1 395ms
18.6 1.63s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.53s Non-interacting
1 0 1 0.31 14.7 1.44s
2 0 2 -0.52 13.1 1.24s
3 0 3 -2.40 11.7 1.12s
4 0 4 -4.46 8.6 881ms
5 0 5 -6.46 5.1 638ms
6 0 6 -8.91 1.0 364ms
7 1 1 -7.81 16.5 1.72s Restart
8 1 2 -8.89 2.1 404ms
18.6 1.64s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.53s Non-interacting
1 0 1 0.31 14.7 1.44s
2 0 2 -0.52 13.1 1.97s
3 0 3 -2.40 11.7 1.06s
4 0 4 -4.46 8.6 823ms
5 0 5 -6.46 5.1 623ms
6 0 6 -8.91 1.0 333ms
7 1 1 -7.81 16.5 1.68s Restart
8 1 2 -8.89 2.1 396ms
18.6 1.63s Final orbitals
Iter Restart Krydim log10(res) avg(CG) Δtime Comment
---- ------- ------ ---------- ------- ------ ---------------
20.0 1.53s Non-interacting
1 0 1 0.31 14.7 1.44s
2 0 2 -0.52 13.1 1.24s
3 0 3 -2.40 11.7 1.14s
4 0 4 -4.46 8.6 900ms
5 0 5 -6.46 5.1 637ms
6 0 6 -8.91 1.0 356ms
7 1 1 -7.81 16.5 1.70s Restart
8 1 2 -8.89 2.1 395ms
18.6 1.63s Final orbitals
107.262952 seconds (137.38 M allocations: 23.451 GiB, 3.26% gc time, 31.53% compilation time)
These are the final phonon frequencies:
phret_q0.frequencies6-element Vector{Float64}:
-0.0034981553584147885
-0.0029774511634385664
-0.0029774511629175257
0.004302230641198312
0.004302230642142157
0.0043532017689935755