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Algirdas Deveikis - One of the best experts on this subject based on the ideXlab platform.
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orthogonalization procedure for antisymmetrization of j shell states
2009Co-Authors: Algirdas DeveikisAbstract:An efficient procedure for construction of the antisymmetric basis of j-shell states with isospin is presented. The basis is represented by one-particle coefficients of fractional parentage (CFPs) employing a simple enumeration scheme of many-particle states. The CFPs are those eigenvectors of the antisymmetrization operator Matrix that correspond with unit eigenvalues. The approach is based on an efficient algorithm of construction of the Idempotent Matrix eigenvectors. The presented algorithm is faster than the diagonalization routine rs() from EISPACK for antisymmetrization procedure applications and is also amenable to parallel calculations.
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a computer program for two particle generalized coefficients of fractional parentage
Computer Physics Communications, 2008Co-Authors: Algirdas Deveikis, A JuodagalvisAbstract:Abstract We present a FORTRAN90 program GCFP for the calculation of the generalized coefficients of fractional parentage (generalized CFPs or GCFP). The approach is based on the observation that the multi-shell CFPs can be expressed in terms of single-shell CFPs, while the latter can be readily calculated employing a simple enumeration scheme of antisymmetric A -particle states and an efficient method of construction of the Idempotent Matrix eigenvectors. The program provides fast calculation of GCFPs for a given particle number and produces results possessing numerical uncertainties below the desired tolerance. A single j -shell is defined by four quantum numbers, ( e , l , j , t ) . A supplemental C++ program parGCFP allows calculation to be done in batches and/or in parallel. Program summary Program title: GCFP , parGCFP Catalogue identifier: AEBI_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEBI_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 17 199 No. of bytes in distributed program, including test data, etc.: 88 658 Distribution format: tar.gz Programming language: FORTRAN 77/90 ( GCFP ), C++ ( parGCFP ) Computer: Any computer with suitable compilers. The program GCFP requires a FORTRAN 77/90 compiler. The auxiliary program parGCFP requires GNU-C++ compatible compiler, while its parallel version additionally requires MPI-1 standard libraries Operating system: Linux (Ubuntu, Scientific) (all programs), also checked on Windows XP ( GCFP , serial version of parGCFP ) RAM: The memory demand depends on the computation and output mode. If this mode is not 4, the program GCFP demands the following amounts of memory on a computer with Linux operating system. It requires around 2 MB of RAM for the A = 12 system at E x ⩽ 2 . Computation of the A = 50 particle system requires around 60 MB of RAM at E x = 0 and ∼ 70 MB at E x = 2 (note, however, that the calculation of this system will take a very long time). If the computation and output mode is set to 4, the memory demands by GCFP are significantly larger. Calculation of GCFPs of A = 12 system at E x = 1 requires 145 MB. The program parGCFP requires additional 2.5 and 4.5 MB of memory for the serial and parallel version, respectively. Classification: 17.18 Nature of problem: The program GCFP generates a list of two-particle coefficients of fractional parentage for several j-shells with isospin. Solution method: The method is based on the observation that multishell coefficients of fractional parentage can be expressed in terms of single-shell CFPs [1]. The latter are calculated using the algorithm [2,3] for a spectral decomposition of an antisymmetrization operator Matrix Y . The coefficients of fractional parentage are those eigenvectors of the antisymmetrization operator Matrix Y that correspond to unit eigenvalues. A computer code for these coefficients is available [4]. The program GCFP offers computation of two-particle multishell coefficients of fractional parentage. The program parGCFP allows a batch calculation using one input file. Sets of GCFPs are independent and can be calculated in parallel. Restrictions: A 86 when E x = 0 (due to the memory constraints); small numbers of particles allow significantly higher excitations, though the shell with j ⩾ 11 / 2 cannot get full (it is the implementation constraint). Unusual features: Using the program GCFP it is possible to determine allowed particle configurations without the GCFP computation. The GCFPs can be calculated either for all particle configurations at once or for a specified particle configuration. The values of GCFPs can be printed out with a complete specification in either one file or with the parent and daughter configurations printed in separate files. The latter output mode requires additional time and RAM memory. It is possible to restrict the ( J , T ) values of the considered particle configurations. (Here J is the total angular momentum and T is the total isospin of the system.) The program parGCFP produces several result files the number of which equals to the number of particle configurations. To work correctly, the program GCFP needs to be compiled to read parameters from the standard input (the default setting). Running time: It depends on the size of the problem. The minimum time is required, if the computation and output mode ( CompMode ) is not 4, but the resulting file is larger. A system with A = 12 particles at E x = 0 (all 9411 GCFPs) took around 1 sec on a Pentium4 2.8 GHz processor with 1 MB L2 cache. The program required about 14 min to calculate all 1.3 × 10 6 GCFPs of E x = 1 . The time for all 5.5 × 10 7 GCFPs of E x = 2 was about 53 hours. For this number of particles, the calculation time of both E x = 0 and E x = 1 with CompMode = 1 and 4 is nearly the same, when no other processes are running. The case of E x = 2 could not be calculated with CompMode = 4, because the RAM memory was insufficient. In general, the latter CompMode requires a longer computation time, although the resulting files are smaller in size. The program parGCFP puts virtually no time overhead. Its parallel version speeds-up the calculation. However, the results need to be collected from several files created for each configuration. References: [1] J. Levinsonas, Works of Lithuanian SSR Academy of Sciences 4 (1957) 17. [2] A. Deveikis, A. Bonckus, R. Kalinauskas, Lithuanian Phys. J. 41 (2001) 3. [3] A. Deveikis, R.K. Kalinauskas, B.R. Barrett, Ann. Phys. 296 (2002) 287. [4] A. Deveikis, Comput. Phys. Comm. 173 (2005) 186. (CPC Catalogue ID. ADWI_v1_0)
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calculation of coefficients of fractional parentage for large basis harmonic oscillator shell model
Annals of Physics, 2002Co-Authors: Algirdas Deveikis, R K Kalinauskas, Bruce R BarrettAbstract:Abstract A new procedure for large-scale calculations of the coefficients of fractional parentage (CFPs) for a single j-orbit with isospin is presented. The approach is based on a simple enumeration scheme for antisymmetric A-particle states and an efficient method for constructing the eigenvectors of an Idempotent Matrix. We investigate the characteristics of the introduced CFP basis and the application of this procedure to the ab initio harmonic-oscillator shell-model approach. The results of CFP calculations for the j=1/2,…,41/2 orbits are presented (the full sets of one-particle and two-particle CFPs up to the j=9/2 orbit are obtained). The new computer code for calculation of the CFPs proves to be very quick, efficient, and numerically stable and produces results possessing only small numerical uncertainties.
Bruce R Barrett - One of the best experts on this subject based on the ideXlab platform.
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calculation of coefficients of fractional parentage for large basis harmonic oscillator shell model
Annals of Physics, 2002Co-Authors: Algirdas Deveikis, R K Kalinauskas, Bruce R BarrettAbstract:Abstract A new procedure for large-scale calculations of the coefficients of fractional parentage (CFPs) for a single j-orbit with isospin is presented. The approach is based on a simple enumeration scheme for antisymmetric A-particle states and an efficient method for constructing the eigenvectors of an Idempotent Matrix. We investigate the characteristics of the introduced CFP basis and the application of this procedure to the ab initio harmonic-oscillator shell-model approach. The results of CFP calculations for the j=1/2,…,41/2 orbits are presented (the full sets of one-particle and two-particle CFPs up to the j=9/2 orbit are obtained). The new computer code for calculation of the CFPs proves to be very quick, efficient, and numerically stable and produces results possessing only small numerical uncertainties.
Deveikis Algirdas - One of the best experts on this subject based on the ideXlab platform.
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A computer program for two-particle generalized coefficients of fractional parentage
2020Co-Authors: Deveikis Algirdas, Juodagalvis AndriusAbstract:We present a FORTRAN90 program GCFP for the calculation of the generalized coefficients of fractional parentage (generalized CFPs or GCFP). The approach is based on the observation that the multi-shell CFPs can be expressed in terms of single-shell CFPs, while the latter can be readily calculated employing a simple enumeration scheme of antisymmetric A-particle states and an efficient method of construction of the Idempotent Matrix eigenvectors. The program provides fast calculation of GCFPs for a given particle number and produces results possessing numerical uncertainties below the desired tolerance. A single j-shell is defined by four quantum numbers. A supplemental C++ program parGCFP allows calculation to be done in batches and/or in parallel. Program summary: Program title: GCFP, parGCFP Catalogue identifier: AEBI_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEBI_v1_0.html Program obtainable from: CPC Program Library, Queen''s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 17 199 No. of bytes in distributed program, including test data, etc.: 88 658 Distribution format: tar.gz Programming language: FORTRAN 77/90 (GCFP), C++ (parGCFP) Computer: Any computer with suitable compilers. The program GCFP requires a FORTRAN 77/90 compiler. The auxiliary program parGCFP requires GNU-C++ compatible compiler, while its parallel version additionally requires MPI-1 standard libraries Operating system: Linux (Ubuntu, Scientific) (all programs), also checked on Windows XP (GCFP, serial version of parGCFP) RAM: The memory demand depends on the computation and output mode. If this mode is not 4, the program GCFP demands the following amounts of memory on a computer with Linux operating system. It requires around 2 MB of RAM for the system at . Computation of the particle system requires aroundVytauto Didžiojo universiteta
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Orthogonalization procedure for antisymmetrization of J-shell states
'Springer Science and Business Media LLC', 2020Co-Authors: Deveikis AlgirdasAbstract:An efficient procedure for construction of the antisymmetric basis of j-shell states with isospin is presented. The basis is represented by one-particle coefficients of fractional parentage (CFPs) employing a simple enumeration scheme of many-particle states. The CFPs are those eigenvectors of the antisymmetrization operator Matrix that correspond with unit eigenvalues. The approach is based on an efficient algorithm of construction of the Idempotent Matrix eigenvectors. The presented algorithm is faster than the diagonalization routine rs() from EISPACK for antisymmetrization procedure applications and is also amenable to parallel calculationsInformatikos fakultetasVytauto Didžiojo universiteta
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A program for generating one-particle and two-particle coefficients of fractional parentage for the single j-orbit with isospin
'Elsevier BV', 2020Co-Authors: Deveikis AlgirdasAbstract:The program CFPjOrbit written in FORTRAN 90 is aimed at generating the list of one-particle and two-particle coefficients of fractional parentage (CFPs) for the single j-orbit with isospin. The approach is based on a simple enumeration scheme for antisymmetric A-particle states and an efficient method for constructing the eigenvectors of an Idempotent Matrix as proposed in [A. Deveikis, R.K. Kalinauskas, B.R. Barrett, Ann. Phys. 296 (2002) 287]. The program provides fast calculation of coefficients of fractional parentage for high j-orbits with isospin and produces results that have only small numerical uncertainties. The auxiliary program EnumCFP allows one to perform enumeration of the coefficientsVytauto Didžiojo universiteta
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Calculation of coefficients of fractional parentage for large-basis harmonic-oscillator shell model
'Elsevier BV', 2020Co-Authors: Deveikis Algirdas, Kalinauskas, Ramutis Kazys, Barrett B. RAbstract:A new procedure for large-scale calculations of the coefficients of fractional parentage (CFPs) for a single j-orbit with isospin is presented, The approach is based on a simple enumeration scheme for antisymmetric A-particle states and an efficient method for constructing the eigenvectors of an Idempotent Matrix. We investigate the characteristics of the introduced CFP basis and the application of this procedure to the ab initio harmonic-oscillator shell-model approach. The results of CFP calculations for the j = 1/ 2,...,41/2 orbits are presented (the full sets of one-particle and two-particle CFPs up to the j = 9/2 orbit are obtained). The new computer code for calculation of the CFPs proves to be very quick, efficient, and numerically stable and produces results possessing only small numerical uncertaintiesFizikos institutasInformatikos fakultetasVytauto Didžiojo universiteta
R K Kalinauskas - One of the best experts on this subject based on the ideXlab platform.
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calculation of coefficients of fractional parentage for large basis harmonic oscillator shell model
Annals of Physics, 2002Co-Authors: Algirdas Deveikis, R K Kalinauskas, Bruce R BarrettAbstract:Abstract A new procedure for large-scale calculations of the coefficients of fractional parentage (CFPs) for a single j-orbit with isospin is presented. The approach is based on a simple enumeration scheme for antisymmetric A-particle states and an efficient method for constructing the eigenvectors of an Idempotent Matrix. We investigate the characteristics of the introduced CFP basis and the application of this procedure to the ab initio harmonic-oscillator shell-model approach. The results of CFP calculations for the j=1/2,…,41/2 orbits are presented (the full sets of one-particle and two-particle CFPs up to the j=9/2 orbit are obtained). The new computer code for calculation of the CFPs proves to be very quick, efficient, and numerically stable and produces results possessing only small numerical uncertainties.
A Juodagalvis - One of the best experts on this subject based on the ideXlab platform.
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a computer program for two particle generalized coefficients of fractional parentage
Computer Physics Communications, 2008Co-Authors: Algirdas Deveikis, A JuodagalvisAbstract:Abstract We present a FORTRAN90 program GCFP for the calculation of the generalized coefficients of fractional parentage (generalized CFPs or GCFP). The approach is based on the observation that the multi-shell CFPs can be expressed in terms of single-shell CFPs, while the latter can be readily calculated employing a simple enumeration scheme of antisymmetric A -particle states and an efficient method of construction of the Idempotent Matrix eigenvectors. The program provides fast calculation of GCFPs for a given particle number and produces results possessing numerical uncertainties below the desired tolerance. A single j -shell is defined by four quantum numbers, ( e , l , j , t ) . A supplemental C++ program parGCFP allows calculation to be done in batches and/or in parallel. Program summary Program title: GCFP , parGCFP Catalogue identifier: AEBI_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEBI_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 17 199 No. of bytes in distributed program, including test data, etc.: 88 658 Distribution format: tar.gz Programming language: FORTRAN 77/90 ( GCFP ), C++ ( parGCFP ) Computer: Any computer with suitable compilers. The program GCFP requires a FORTRAN 77/90 compiler. The auxiliary program parGCFP requires GNU-C++ compatible compiler, while its parallel version additionally requires MPI-1 standard libraries Operating system: Linux (Ubuntu, Scientific) (all programs), also checked on Windows XP ( GCFP , serial version of parGCFP ) RAM: The memory demand depends on the computation and output mode. If this mode is not 4, the program GCFP demands the following amounts of memory on a computer with Linux operating system. It requires around 2 MB of RAM for the A = 12 system at E x ⩽ 2 . Computation of the A = 50 particle system requires around 60 MB of RAM at E x = 0 and ∼ 70 MB at E x = 2 (note, however, that the calculation of this system will take a very long time). If the computation and output mode is set to 4, the memory demands by GCFP are significantly larger. Calculation of GCFPs of A = 12 system at E x = 1 requires 145 MB. The program parGCFP requires additional 2.5 and 4.5 MB of memory for the serial and parallel version, respectively. Classification: 17.18 Nature of problem: The program GCFP generates a list of two-particle coefficients of fractional parentage for several j-shells with isospin. Solution method: The method is based on the observation that multishell coefficients of fractional parentage can be expressed in terms of single-shell CFPs [1]. The latter are calculated using the algorithm [2,3] for a spectral decomposition of an antisymmetrization operator Matrix Y . The coefficients of fractional parentage are those eigenvectors of the antisymmetrization operator Matrix Y that correspond to unit eigenvalues. A computer code for these coefficients is available [4]. The program GCFP offers computation of two-particle multishell coefficients of fractional parentage. The program parGCFP allows a batch calculation using one input file. Sets of GCFPs are independent and can be calculated in parallel. Restrictions: A 86 when E x = 0 (due to the memory constraints); small numbers of particles allow significantly higher excitations, though the shell with j ⩾ 11 / 2 cannot get full (it is the implementation constraint). Unusual features: Using the program GCFP it is possible to determine allowed particle configurations without the GCFP computation. The GCFPs can be calculated either for all particle configurations at once or for a specified particle configuration. The values of GCFPs can be printed out with a complete specification in either one file or with the parent and daughter configurations printed in separate files. The latter output mode requires additional time and RAM memory. It is possible to restrict the ( J , T ) values of the considered particle configurations. (Here J is the total angular momentum and T is the total isospin of the system.) The program parGCFP produces several result files the number of which equals to the number of particle configurations. To work correctly, the program GCFP needs to be compiled to read parameters from the standard input (the default setting). Running time: It depends on the size of the problem. The minimum time is required, if the computation and output mode ( CompMode ) is not 4, but the resulting file is larger. A system with A = 12 particles at E x = 0 (all 9411 GCFPs) took around 1 sec on a Pentium4 2.8 GHz processor with 1 MB L2 cache. The program required about 14 min to calculate all 1.3 × 10 6 GCFPs of E x = 1 . The time for all 5.5 × 10 7 GCFPs of E x = 2 was about 53 hours. For this number of particles, the calculation time of both E x = 0 and E x = 1 with CompMode = 1 and 4 is nearly the same, when no other processes are running. The case of E x = 2 could not be calculated with CompMode = 4, because the RAM memory was insufficient. In general, the latter CompMode requires a longer computation time, although the resulting files are smaller in size. The program parGCFP puts virtually no time overhead. Its parallel version speeds-up the calculation. However, the results need to be collected from several files created for each configuration. References: [1] J. Levinsonas, Works of Lithuanian SSR Academy of Sciences 4 (1957) 17. [2] A. Deveikis, A. Bonckus, R. Kalinauskas, Lithuanian Phys. J. 41 (2001) 3. [3] A. Deveikis, R.K. Kalinauskas, B.R. Barrett, Ann. Phys. 296 (2002) 287. [4] A. Deveikis, Comput. Phys. Comm. 173 (2005) 186. (CPC Catalogue ID. ADWI_v1_0)
