Hello, I am a Computer Science student and am working on a nuclear physics code. Actually I am not a physics guy but need to have a very basic understanding of some nuclear physics terms. I am reading a paper on this project and need your help in understanding some concepts. Some of these terms are: many body interaction, Hamiltonian and large harmonic oscillator(and how are these related), basis states(single particle basis state etc.), wavefunctions, basis functions and how they are useful in matrix vector multiplication, (somehow all these suggest a matrix or a vector I guess). My task is basically related to matrix multiplication and optimization and speed up of the program by using parallel IO. I know these questions may be a bit too much to explain in layman's terms but whatever help you all can give could be of great help. Some of the methods mentioned in the paper which I have no clue about are: 1. Expand nuclear wave function in H.O. basis functions 2. Generate Many–Body basis Slater-Determinant of single particle states Carbon-12 using 8 H.O. levels: 33 million basis states 3. Construct Many–Body Hamiltonian from 2-body (and 3-body) interactions I have little knowledge of nuclear physics that I had learned a long time back. Kindly provide some explanations that I can relate to as a computer science student. Thanks.