%0 Journal Article %1 Chang2014339 %A Chang, Yuan-Pin %A Filsinger, Frank %A Sartakov, Boris G. %A Küpper, Jochen %D 2014 %J Computer Physics Communications %K computation field physics programming python software spectroscopy strong unread %N 1 %P 339 - 349 %R 10.1016/j.cpc.2013.09.001 %T CMIstark: Python package for the Stark-effect calculation and symmetry classification of linear, symmetric and asymmetric top wavefunctions in dc electric fields %U http://www.sciencedirect.com/science/article/pii/S0010465513003019 %V 185 %X Abstract The Controlled Molecule Imaging group (CMI) at the Center for Free Electron Laser Science (CFEL) has developed the \CMIstark\  software to calculate, view, and analyze the energy levels of adiabatic Stark energy curves of linear, symmetric top and asymmetric top molecules. The program exploits the symmetry of the Hamiltonian to generate fully labeled adiabatic Stark energy curves. \CMIstark\  is written in Python and easily extendable, while the core numerical calculations make use of machine optimized \BLAS\ and ŁAPACK\ routines. Calculated energies are stored in \HDF5\ files for convenient access and programs to extract \ASCII\ data or to generate graphical plots are provided. Program summary Program title: \CMIstark\ Catalogue identifier: AEQS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEQS_v1_0.html Program obtainable from: \CPC\ Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: \GNU\ General Public License version 3 or later with amendments. See code for details. No. of lines in distributed program, including test data, etc.: 4091 No. of bytes in distributed program, including test data, etc.: 62805 Distribution format: tar.gz Programming language: Python (version 2.6.x, 2.7.x). Computer: Any Macintosh, PC, or Linux/UNIX workstations with a modern Python distribution. Operating system: Tested on Mac ØS\ X and a variety of Linux distributions. RAM: 2 \GB\ for typical calculations Classification: 16.1. External routines: Python packages numpy and scipy; utilizes (optimized) ŁAPACK\ and \BLAS\ through scipy. All packages available under open-source licenses. Nature of problem: Calculation of the Stark effect of asymmetric top molecules in arbitrarily strong dc electric fields in a correct symmetry classification and using correct labeling of the adiabatic Stark curves. Solution method: We set up the full M matrices of the quantum-mechanical Hamiltonian in the basis set of symmetric top wavefunctions and, subsequently, Wang transform the Hamiltonian matrix. We separate, as far as possible, the sub-matrices according to the remaining symmetry, and then diagonalize the individual blocks. This application of the symmetry consideration to the Hamiltonian allows an adiabatic correlation of the asymmetric top eigenstates in the dc electric field to the field-free eigenstates. This directly yields correct adiabatic state labels and, correspondingly, adiabatic Stark energy curves. Restrictions: The maximum value of J is limited by the available main memory. A modern desktop computer with 16 GB of main memory allows for calculations including all J s up to a values larger than 100 even for the most complex cases of asymmetric tops. Running time: Typically 1 s–1 week on a single \CPU\ or equivalent on multi-CPU systems (depending greatly on system size and RAM); parallelization through BLAS/LAPACK. For instance, calculating all energies up to J = 25 of indole (vide infra) for one field strength takes 1 CPU-s on a current iMac.

@article{Chang2014339, abstract = {Abstract The Controlled Molecule Imaging group (CMI) at the Center for Free Electron Laser Science (CFEL) has developed the \{CMIstark\}  software to calculate, view, and analyze the energy levels of adiabatic Stark energy curves of linear, symmetric top and asymmetric top molecules. The program exploits the symmetry of the Hamiltonian to generate fully labeled adiabatic Stark energy curves. \{CMIstark\}  is written in Python and easily extendable, while the core numerical calculations make use of machine optimized \{BLAS\} and \{LAPACK\} routines. Calculated energies are stored in \{HDF5\} files for convenient access and programs to extract \{ASCII\} data or to generate graphical plots are provided. Program summary Program title: \{CMIstark\} Catalogue identifier: AEQS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEQS_v1_0.html Program obtainable from: \{CPC\} Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: \{GNU\} General Public License version 3 or later with amendments. See code for details. No. of lines in distributed program, including test data, etc.: 4091 No. of bytes in distributed program, including test data, etc.: 62805 Distribution format: tar.gz Programming language: Python (version 2.6.x, 2.7.x). Computer: Any Macintosh, PC, or Linux/UNIX workstations with a modern Python distribution. Operating system: Tested on Mac \{OS\} X and a variety of Linux distributions. RAM: 2 \{GB\} for typical calculations Classification: 16.1. External routines: Python packages numpy and scipy; utilizes (optimized) \{LAPACK\} and \{BLAS\} through scipy. All packages available under open-source licenses. Nature of problem: Calculation of the Stark effect of asymmetric top molecules in arbitrarily strong dc electric fields in a correct symmetry classification and using correct labeling of the adiabatic Stark curves. Solution method: We set up the full M matrices of the quantum-mechanical Hamiltonian in the basis set of symmetric top wavefunctions and, subsequently, Wang transform the Hamiltonian matrix. We separate, as far as possible, the sub-matrices according to the remaining symmetry, and then diagonalize the individual blocks. This application of the symmetry consideration to the Hamiltonian allows an adiabatic correlation of the asymmetric top eigenstates in the dc electric field to the field-free eigenstates. This directly yields correct adiabatic state labels and, correspondingly, adiabatic Stark energy curves. Restrictions: The maximum value of J is limited by the available main memory. A modern desktop computer with 16 GB of main memory allows for calculations including all J s up to a values larger than 100 even for the most complex cases of asymmetric tops. Running time: Typically 1 s–1 week on a single \{CPU\} or equivalent on multi-CPU systems (depending greatly on system size and RAM); parallelization through BLAS/LAPACK. For instance, calculating all energies up to J = 25 of indole (vide infra) for one field strength takes 1 CPU-s on a current iMac. }, added-at = {2014-01-13T04:22:58.000+0100}, author = {Chang, Yuan-Pin and Filsinger, Frank and Sartakov, Boris G. and Küpper, Jochen}, biburl = {https://www.bibsonomy.org/bibtex/24a156fe11b9188646f703fbebc5f6a67/drmatusek}, doi = {10.1016/j.cpc.2013.09.001}, interhash = {4ec4ddb61cc96ff1802a1a62281d3b23}, intrahash = {4a156fe11b9188646f703fbebc5f6a67}, issn = {0010-4655}, journal = {Computer Physics Communications }, keywords = {computation field physics programming python software spectroscopy strong unread}, month = jan, number = 1, pages = {339 - 349}, timestamp = {2014-01-13T04:22:58.000+0100}, title = {CMIstark: Python package for the Stark-effect calculation and symmetry classification of linear, symmetric and asymmetric top wavefunctions in dc electric fields }, url = {http://www.sciencedirect.com/science/article/pii/S0010465513003019}, volume = 185, year = 2014 }