# Revised calculation of four-particle harmonic-oscillator transformation brackets matrix

## Description

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract In this article we present a new, considerably enhanced and more rapid method for calculation of the matrix of four-particle harmonic-oscillator transformation brackets (4HOB). The new method is an improved version of 4HOB matrix calculations which facilitates the matrix calculation by finding the eigenvectors of the 4HOB matrix explicitly. Using this idea the new Fortran code for fast and 4HOB matrix calculation is presented. The calculation time decreases more than a few hundred times for l... Title of program: HOTB_M Catalogue Id: AEFQ_v3_0 Nature of problem Calculation of the matrix of 4HOB in a more effective way, which allows us to calculate matrix of the brackets up to a few hundred times more rapidly than in a previous version. Versions of this program held in the CPC repository in Mendeley Data AEFQ_v1_0; HOTB; 10.1016/j.cpc.2009.10.012 AEFQ_v2_0; HOTB; 10.1016/j.cpc.2011.01.031 AEFQ_v3_0; HOTB_M; 10.1016/j.cpc.2012.09.021 AEFQ_v4_0; HOTB_MPI; 10.1016/j.cpc.2014.06.025