From ccee9c38ea4ce0a1400c29d2ecd04a011f051799 Mon Sep 17 00:00:00 2001
From: Nuwan Yapa <yapanuwan@gmail.com>
Date: Mon, 1 Apr 2024 18:56:59 -0400
Subject: [PATCH] 2-body calculation for benchmarking 3-body

---
 ho_basis_2body.jl | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 ho_basis_2body.jl

diff --git a/ho_basis_2body.jl b/ho_basis_2body.jl
new file mode 100644
index 0000000..f1ed433
--- /dev/null
+++ b/ho_basis_2body.jl
@@ -0,0 +1,31 @@
+using Arpack, SparseArrays
+include("ho_basis.jl")
+include("p_space.jl")
+
+E_max = 30
+ω = 0.2
+Λ = 0
+m = 1.0
+
+Va = -2
+Ra = 2
+
+μ1 = m * 1/2
+
+println("No of threads = ", Threads.nthreads())
+
+Es, n1s, l1s = get_sp_basis(E_max)
+println("Basis size = ", length(Es))
+
+println("Constructing KE matrices")
+@time "T1" T1 = sp_T_matrix(n1s, l1s; ω=ω, μ=μ1)
+
+println("Constructing PE matrices")
+V1_elem(l, n1, n2) = Va * V_Gaussian(Ra, l, n1, n2; ω=ω)
+@time "V1" V1 = sp_V_matrix(V1_elem, n1s, l1s)
+
+println("Calculating spectrum")
+@time "H" H = T1 + V1
+@time "Eigenvalues" evals, _ = eigs(H, nev=3, ncv=30, which=:SR, maxiter=5000, tol=1e-5, ritzvec=false, check=1)
+
+display(evals)
\ No newline at end of file