model = sqw_cubic_monoatomic(p, h,k,l,w, {signal}) : cubic monoatomic dispersion(HKL) with DHO(energy)
iFunc/sqw_cubic_monoatomic: a 4D S(q,w) with a HKL dispersion, and a DHO line
shape, for a simple monoatomic system on a cubic lattice. Only the 3
acoustic modes are computed.
WARNING:
Single intensity and line width parameters are used here.
The HKL position is relative to the closest Bragg peak.
Example:
s=sqw_cubic_monoatomic([2 3]); qh=linspace(0,.5,50);qk=qh; ql=qh; w=linspace(0.01,10,51);
f=iData(s,[],qh,qk,ql,w); scatter3(log(f(:,:,1,:)),'filled');
References: https://en.wikipedia.org/wiki/Phonon
E. Meisterhofer <http://lampx.tugraz.at/~hadley/ss1/phonons/scdos/sc.pdf> 2013
Kittel, Solid State Physics, Wiley, New York, 7th ed. (1996), pp 99-103.
input: p: sqw_cubic_monoatomic model parameters (double)
p(1)=C_ratio C1/C2 force constant ratio first/second neighbours.
p(2)=E0 sqrt(C1/m) energy [meV]
p(3)=Gamma dispersion DHO half-width in energy [meV]
p(4)=Temperature of the material [K]
p(5)=Amplitude
p(6)=Background (constant)
qh: axis along QH in rlu (row,double)
qk: axis along QK in rlu (column,double)
ql: axis along QL in rlu (page,double)
w: axis along energy in meV (double)
signal: when values are given, a guess of the parameters is performed (double)
output: signal: model value
Version: Aug. 22, 2017
See also iData, iFunc/fits, iFunc/plot, gauss, sqw_phonons, sqw_sine3d, sqw_vaks
<a href="matlab:doc(iFunc,'Models')">iFunc:Models</a>
(c) E.Farhi, ILL. License: EUPL.