BergEC-jl/ho_basis.jl

109 lines
3.0 KiB
Julia

using SparseArrays
using NuclearToolkit
using SpecialFunctions
include("helper.jl")
# Gaussian potentials in HO space
inv_factorial(n) = Iterators.prod(inv.(1:n))
sqrt_factorial(n) = Iterators.prod(sqrt.(n:-1:1))
N_lnk(l, n, k) = 1/sqrt_factorial(n) * binomial(n, k) * sqrt(gamma(n + l + 3/2)) / gamma(k + l + 3/2)
Talmi(l, R, k1, k2; ω=1.0) = (-1)^(k1 + k2) * (1 + 1/(ω * R^2))^-(3/2 + l + k1 + k2) * gamma(3/2 + l + k1 + k2)
V_Gaussian(R, l, n1, n2; ω=1.0) = (-1)^(n1 + n2) * better_sum([N_lnk(l, n1, k1) * N_lnk(l, n2, k2) * Talmi(l, R, k1, k2; ω=ω) for (k1, k2) in Iterators.product(0:n1, 0:n2)])
function get_sp_basis(E_max)
Es = Int[]
ns = Int[]
ls = Int[]
# E = 2*n + l
for E in 0 : E_max
for n in 0 : E ÷ 2
l = E - 2*n
push!(Es, E)
push!(ns, n)
push!(ls, l)
end
end
return (Es, ns, ls)
end
function get_2p_basis(E_max)
Es = Int[]
n1s = Int[]
l1s = Int[]
n2s = Int[]
l2s = Int[]
# E = 2*n1 + l1 + 2*n2 + l2
for E in 0 : 2*E_max
for n1 in 0 : E ÷ 2
for n2 in 0 : (E - 2*n1) ÷ 2
for l1 in 0 : (E - 2*n1 - 2*n2)
l2 = E - 2*n1 - 2*n2 - l1
push!(Es, E)
push!(n1s, n1)
push!(l1s, l1)
push!(n2s, n2)
push!(l2s, l2)
end
end
end
end
return (Es, n1s, l1s, n2s, l2s)
end
function sp_T_matrix(ns, ls; ω=1.0, μ=1.0)
mat = spzeros(length(ns), length(ns))
for idx in CartesianIndices(mat)
(i, j) = Tuple(idx)
if ls[i] == ls[j]
mat[idx] = ls[i]
if ns[i] == ns[j]
mat[idx] += 1/4 * (4*ns[j] + 3)
elseif ns[i] == ns[j] + 1
mat[idx] += -1/4 * sqrt((2*ns[j] + 2) * (2*ns[j] + 3))
elseif ns[i] == ns[j] - 1
mat[idx] += -1/4 * sqrt((2*ns[j] + 1) * 2*ns[j])
end
end
end
return (ω / μ) .* mat
end
function sp_V_matrix(V_l, ns, ls; dtype=Float64)
mat = spzeros(dtype, length(ns), length(ns))
for idx in CartesianIndices(mat)
(i, j) = Tuple(idx)
if ls[i] == ls[j]
mat[idx] = V_l(ls[i], ns[i], ns[j])
end
end
return mat
end
function Moshinsky_transform(Es, n1s, l1s, n2s, l2s, Λ)
E_max = maximum(Es)
j_max = 2 * E_max + 1
l_max = j_max
to = 0 # unused
dtri = NuclearToolkit.prep_dtri(l_max + 1);
dcgm0 = NuclearToolkit.prep_dcgm0(l_max);
d6j = nothing # NuclearToolkit.prep_d6j_int(E_max, j_max, to);
mat = spzeros(length(Es), length(Es))
s = hcat(Es, n1s, l1s, n2s, l2s)
for idx in CartesianIndices(mat)
(i, j) = Tuple(idx)
(Elhs, N, L, n, l) = s[i, :]
(Erhs, n1, l1, n2, l2) = s[j, :]
if Elhs == Erhs
mat[i, j] = NuclearToolkit.HObracket_d6j(N, L, n, l, n1, l1, n2, l2, Λ, 1.0, dtri, dcgm0, d6j)
end
end
return mat
end