A system to generate fortran programs for calculating configuration traces of angular momentum coupled product operators

Abstract

We present a program in C that employs spectral distribution theory for studies of characteristic properties of a many-particle quantum-mechanical system and the underlying few-body interaction. In particular, the program focuses on two-body nuclear interactions given in a JT-coupled harmonic oscillator basis and calculates correlation coefficients, a measure of similarity of any two interactions, as well as Hilbert–Schmidt norms specifying interaction strengths. An important feature of the program is its ability to identify the monopole part (centroid) of a 2-body interaction, as well as its ‘density-dependent’ one-body and two-body part, thereby providing key information on the evolution of shell gaps and binding energies for larger nuclear systems. As additional features, we provide statistical measures for ‘density-dependent’ interactions, as well as a mechanism to express an interaction in terms of two other interactions. This, in turn, allows one to identify, e.g., established features of the nuclear interaction (such as pairing correlations) within a general Hamiltonian. The program handles the radial degeneracy for ‘density-dependent’ one-body interactions and together with an efficient linked list data structure, facilitates studies of nuclear interactions in large model spaces that go beyond valence-shell applications.Program title: sdtCatalogue identifier: AEQG_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEQG_v1_0.htmlProgram obtainable from: CPC Program Library, Queen’s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 10 888No. of bytes in distributed program, including test data, etc.: 88 778Distribution format: tar.gzProgramming language: C.Computer: Laptop, Workstation.Operating system: Linux [tested on Linux (Kernel 2.6.9) with a gcc, version 3.4.6].RAM: Less than 10 MBClassification: 17.15.Nature of problem:The program calculates second-order energy moments, such as variances and correlation coefficients, widely used as measures of the overall strength of an interaction and its similarity to other interactions. It allows for studies of the physical properties of various interactions and their effect on many-particle systems.Solution method:Calculations are based on spectral distribution theory and invoke statistical measures provided by the theory.Running time:Less than 20 min (typically, several seconds) using a 1.80 GHz processor.