FARM_2DRMP: A version of FARM for use with 2DRMP

To complete the 2DRMP package an asymptotic program, such as FARM, is needed. The original version of FARM is designed to construct the physical R-matrix, R, from surface amplitudes contained in the H-file. However, in 2DRMP, R has already been constructed for each scattering energy during propagation. Therefore, this modified version of FARM, known as FARM_2DRMP, has been developed solely for use with 2DRMP.

New version program summary

Program title: FARM_2DRMPCatalogue identifier: ADAZ_v1_1Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADAZ_v1_1.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.: 13 806No. of bytes in distributed program, including test data, etc.: 134 462Distribution format: tar.gzProgramming language: Fortran 95 and MPIComputer: Tested on CRAY XT4 [1]; IBM eServer 575 [2]; Itanium II cluster [3]Operating system: Tested on UNICOS/lc [1]; IBM AIX [2]; Red Hat Linux Enterprise AS [3]Has the code been vectorized or parallelized?: Yes. 16 cores were used for the small test runClassification: 2.4External routines: BLAS, LAPACKDoes the new version supersede the previous version?: NoNature of problem: The program solves the scattering problem in the asymptotic region of R-matrix theory where exchange is negligible.Solution method: A radius is determined at which the wave function, calculated as a Gailitis expansion [4] with accelerated summing [5] over terms, converges. The R-matrix is propagated from the boundary of the internal region to this radius and the K-matrix calculated. Collision strengths or cross sections may be calculated.Reasons for new version: To complete the 2DRMP package [6] an asymptotic program, such as FARM [7], is needed. The original version of FARM is designed to construct the physical R-matrix, R, from surface amplitudes contained in the H-file. However, in 2DRMP, R, has already been constructed for each scattering energy during propagation and each R is stored in one of the RmatT files described in Fig. 8 of [6]. Therefore, this modified version of FARM, known as FARM_2DRMP, has been developed solely for use with 2DRMP. Instructions on its use and corresponding test data is provided with 2DRMP [6].Summary of revisions: FARM_2DRMP contains two codes, farm.f and farm_par.f90. The former is a serial code while the latter is a parallel F95 code that employs an MPI harness to enable the nenergy energies to be computed simultaneously across ncore cores, with each core processing either ⌊nenergy/ncore⌋ or ⌈nenergy/ncore⌉ energies. The input files, input.d and H, and the output file farm.out are as described in [7]. Both codes read R directly from RmatT.Restrictions: FARM_2DRMP is for use solely with 2DRMP and for a specified L,S and Π combination. The energy range specified in input.d must match that specified in energies.data.Running time: The wall clock running time for the small test run using 16 cores and performed on [3] is 9 secs.References:

• [1] 

  HECToR, CRAY XT4 running UNICOS/lc, http://www.hector.ac.uk/, visited 22 July, 2009.

• [2] 

  HPCx, IBM eServer 575 running IBM AIX, http://www.hpcx.ac.uk/, visited 22 July, 2009.

• [3] 

  HP Cluster, Itanium II cluster running Red Hat Linux Enterprise AS, Queen's University Belfast, http://www.qub.ac.uk/directorates/InformationServices/Research/HighPerformanceComputing/Services/Hardware/HPResearch/, visited 22 July, 2009.

• [4] 

  M. Gailitis, J. Phys. B 9 (1976) 843.

• [5] 

  C.J. Noble, R.K. Nesbet, Comput. Phys. Comm. 33 (1984) 399.

• [6] 

  N.S. Scott, M.P. Scott, P.G. Burke, T. Stitt, V. Faro-Maza, C. Denis, A. Maniopoulou, Comput. Phys. Comm. 180 (12) (2009) 2424–2449, this issue.

• [7] 

  V.M. Burke, C.J. Noble, Comput. Phys. Comm. 85 (1995) 471.