diff --git a/misc/finiterectlat-modes.py b/misc/finiterectlat-modes.py
new file mode 100755
index 0000000..b62068e
--- /dev/null
+++ b/misc/finiterectlat-modes.py
@@ -0,0 +1,115 @@
+#!/usr/bin/env python3
+
+import math
+from qpms.argproc import ArgParser
+
+
+ap = ArgParser(['rectlattice2d_finite', 'single_particle', 'single_lMax', ])
+
+ap.add_argument("-t", "--rank-tolerance", type=float, default=1e11)
+ap.add_argument("-c", "--min-candidates", type=int, default=1, help='always try at least this many eigenvalue candidates, even if their SVs in the rank tests are lower than rank_tolerance')
+ap.add_argument("-T", "--residual-tolerance", type=float, default=0.)
+
+ap.add_argument("-o", "--output", type=str, required=False, help='output path (if not provided, will be generated automatically)')
+#ap.add_argument("-O", "--plot-out", type=str, required=False, help="path to plot output (optional)")
+#ap.add_argument("-P", "--plot", action='store_true', help="if -p not given, plot to a default path")
+#ap.add_argument("-g", "--save-gradually", action='store_true', help="saves the partial result after computing each irrep")
+
+ap.add_argument("-f", "--centre", type=complex, required=True, help='Contour centre in eV')
+ap.add_argument("--ai", type=float, default=0.05, help="Contour imaginary half-axis in eV")
+ap.add_argument("--ar", type=float, default=0.05, help="Contour real half-axis in eV")
+ap.add_argument("-N", type=int, default="150", help="Integration contour discretisation size")
+
+ap.add_argument("--irrep", type=str, nargs=1, default="none", help="Irrep subspace (irrep index from 0 to 7, irrep label, or 'none' for no irrep decomposition")
+
+a=ap.parse_args()
+
+import logging
+logging.basicConfig(format='%(asctime)s %(message)s', level=logging.INFO)
+
+Nx, Ny = a.size
+px, py = a.period
+
+particlestr = ("sph" if a.height is None else "cyl") + ("_r%gnm" % (a.radius*1e9))
+if a.height is not None: particlestr += "_h%gnm" % (a.height * 1e9)
+defaultprefix = "%s_p%gnmx%gnm_%dx%d_m%s_n%g_L%d_c(%s±%g±%gj)eV_cn%d" % (
+    particlestr, px*1e9, py*1e9, Nx, Ny, str(a.material), a.refractive_index, a.lMax,
+    str(a.centre), a.ai, a.ar, a.N)
+logging.info("Default file prefix: %s" % defaultprefix)
+
+
+import numpy as np
+import qpms
+from qpms.cybspec import BaseSpec
+from qpms.cytmatrices import CTMatrix, TMatrixGenerator
+from qpms.qpms_c import Particle
+from qpms.cymaterials import EpsMu, EpsMuGenerator, LorentzDrudeModel, lorentz_drude
+from qpms.cycommon import DebugFlags, dbgmsg_enable
+from qpms import FinitePointGroup, ScatteringSystem, BesselType, eV, hbar
+from qpms.symmetries import point_group_info
+eh = eV/hbar
+
+dbgmsg_enable(DebugFlags.INTEGRATION)
+
+#Particle positions
+orig_x = (np.arange(Nx/2) + (0 if (Nx % 2) else .5)) * px
+orig_y = (np.arange(Ny/2) + (0 if (Ny % 2) else .5)) * py
+
+orig_xy = np.stack(np.meshgrid(orig_x, orig_y), axis = -1)
+
+
+bspec = BaseSpec(lMax = a.lMax)
+medium = EpsMuGenerator(ap.background_epsmu)
+particles= [Particle(orig_xy[i], ap.tmgen, bspec) for i in np.ndindex(orig_xy.shape[:-1])]
+
+sym = FinitePointGroup(point_group_info['D2h'])
+logging.info("Creating scattering system object")
+ss, ssw = ScatteringSystem.create(particles, medium, sym, a.centre * eh)
+
+if a.irrep == 'none':
+    iri = None # no irrep decomposition
+    irname = 'full'
+    logging.info("Not performing irrep decomposition and working with the full space of dimension %d." % ss.fecv_size)
+else:
+    try:
+        iri = int(a.irrep)
+    except ValueError:
+        iri = ss.irrep_names.index(a.irrep)
+    irname = ss.irrep_names(iri)
+    logging.info("Using irrep subspace %s (iri = %d) of dimension %d." % (irname, iri, ss.saecv_sizes[iri]))
+
+outfile_tmp = defaultprefix + ".tmp" if a.output is None else a.output + ".tmp"
+
+logging.info("Starting Beyn's algorithm")
+results = ss.find_modes(iri=iri, omega_centre = a.centre*eh, omega_rr=a.ar*eh, omega_ri=a.ai*eh, contour_points=a.N,
+        rank_tol=a.rank_tolerance, rank_min_sel=a.min_candidates, res_tol=a.residual_tolerance)
+results['inside_contour'] = inside_ellipse((results['eigval'].real, results['eigval'].imag)
+        (a.centre.real*eh, a.centre.imag*eh), (a.ar*eh, a.ai*eh))
+results['refractive_index_internal'] = [medium(om).n for om in results['eigval']]
+
+outfile = defaultprefix + (('_ir%s_%s.npz' % (str(iri), irname)) if iri is not None else '.npz') if a.output is None else a.output
+np.savez(outfile, meta=vars(a), **results)
+logging.info("Saved to %s" % outfile)
+
+exit(0)
+
+# TODO plots.
+if a.plot or (a.plot_out is not None):
+    import matplotlib
+    matplotlib.use('pdf')
+    from matplotlib import pyplot as plt
+
+    fig = plt.figure()
+    ax = fig.add_subplot(111)
+    ax.plot(sinalpha_list, σ_ext*1e12,label='$\sigma_\mathrm{ext}$')
+    ax.plot(sinalpha_list, σ_scat*1e12, label='$\sigma_\mathrm{scat}$')
+    ax.plot(sinalpha_list, σ_abs*1e12, label='$\sigma_\mathrm{abs}$')
+    ax.legend()
+    ax.set_xlabel('$\sin\\alpha$')
+    ax.set_ylabel('$\sigma/\mathrm{\mu m^2}$')
+    
+    plotfile = defaultprefix + ".pdf" if a.plot_out is None else a.plot_out
+    fig.savefig(plotfile)
+
+exit(0)
+