Ok so I'm a complete beginner in computational modelling (I use analytical methods of physics typically) but I would like to model an anisotropic, aperiodic (but not random) finite array of metallic nanorods, all of which have their long axis orientated in the same direction as eachother, but this direction can be completely arbitrary.
What I am interested in is the charge oscillations in each nanorod (localised surface plasmons) which can electromagnetically couple to neighbouring nanorods and generate a collective charge density wave (plasmon/polariton) which can in principle propagate through the system. For example I could impose a periodic driving of the charge density in one nanorod at a particular frequency and see how it decomposes into the different allowed momentum states of the system and propagates. I want to have a simulation where I can see the propagation of these waves.
The problem is that because of the aperiodicity I can't use periodic boundary conditions. I believe this means that a full 3D electromagnetic simulation is too computationally heavy (I have a good spec iMac but nothing better). So I assume I have to do a 2D model, but I have no idea if this makes any sense for my system and how to implement. These nanorods in principle can have any orientation in 3-dimensions and the EM field is intrinsically 3D so how can I map this problem to 2D. How reliable is this approach for modelling the reality?
I'm hoping for some suggestions on what software to use and how to get started and perhaps some insight into this 3D to 2D mapping problem. I have access to COMSOl but happy to try other (free) software.