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Betaofnu - Program Instructions The program instructions are also downloaded when one downloads the program. c PROGRAM INSTRUCTIONS c c Consider a diatomic molecule in an initial electronic state which is c excited by linearly polarized light to a dissociative electronic c state and subsequently dissociates to give products at an angle c theta relative to the axis of linearly polarized light. c The angular distribution is described as c I(theta)= (1/4pi)(1 + Beta P2(cos(theta)) ). c This program calculates both 1) the variation of Beta with wavenumber c and 2) a spectral simulation for an individual vibrational band of a c selected electronic trasition. c c c The program works in a Hund's case (a) basis set and expands other c cases in terms of these. It decides what to do based on the c spectral parameters. c c Nuclear spin statistics have not been included in determining the c initial populations. If desired, the function Pop(J,P,F,M) can be c modified to include them. An example is presented in c comments in that function. c c There is substantial input from the user needed. c The needed information is all obtained by reading an external file named c betaofnuin.dat, whose description is given here. Output is written c to a file called results.dat c c * First line: c Any notations that you would like to appear on the first line c of the output file (results.dat) c c * Second line: c A second line of any notations that you would like to appear on c the second line of the output file (results.dat) c c * Third line: c This line contains information on the initial electronic c state. Three numbers (F12.8) separated by commas. c The first is the spin S for the initial electronic state, c the second is Lambda for the initial state. The third is c the parity. A number +/- 1.0 must appear for the parity, c but it is used only if Lambda=0 (other states have both parities). c For example, a Double Pi state would have a line reading c 0.5, 1.0, 1.0 c and a Singlet Sigma Minus would have a line reading c 0.0, 0.0, -1.0 c Note that the program is currently set up to do the following c initial (or final) states: c Singlet Sigma (plus or minus) c Singlet Pi, Delta, or Phi c Doublet Sigma, Pi, or Delta c Triplet Sigma (though I think Pi and Delta are similar) c Other states require modification of the program c c * Fourth line: c Provide similar information to the first line, except c provided for the upper, dissociative state. Three numbers (F12.8). c c * Fifth line: c Two floating point numbers (F12.8), Jmin and Jmax. These provide c the range of initial state J values over which the results will be c summed. This range should be large enough to include all rotational c levels which, when connected to the upper state, have transition c frequencies whose broadened lines have amplitude at frequencies c within the spectral range desired in the simulation. Recall that c the contributions from these lines are weighted by their Boltzmann c factors. The time the program takes depends critically on Jmax and c scales roughly as 2Jmax+1. The maximum value of Jmax that the c program can currently handle is 49. Note that the values Jmin and c Jmax may be either integral or half integral, depending on the c electronic spin. The program does normal calculations for Jmax up c to 25 (24.5, if spin=.5), but it makes approximations after this. Note c also that the time for running the program is strongly dependent on Jmax. c c * Sixth line: c Two integers (I5) giving nangdist, the number of elements in the c angular distribution, and nspect, the number of elements in the c spectral distribution. For normal operation, you should set nangdist=3; c this provides the best accuracy at the fastest speed. The ONLY reason c not to do this is if you want to output a nice angular distribution at each c spectral point using icntrl=2 (see line 16 below). c The value of nspect c depends on the spectral resolution. It should probably c be at least large enough to give several points within each c line breadth. c c * Seventh line: c An integer (I5) and 4 real (F12.5) numbers. c The integer: ifano = 1 for Fano lineshapes, and ifano=0 c for Lorentzian ones. c A real number: dnu (also called gamma), the Lorentz broadening paramater c Two real numbers, g and q for the Fano lineshape c One real number for the Temperature in K c NB: the program expects all five numbers, even though not all are used for c a particular case. Set g and q to zero for ifano=0 or dnu to zero for c ifano=1 c c * Eighth line: c Two floating point numbers (F12.8) Bin and Bfin, the rotational c constants in cm-1 for the initial and dissociative electronic c states. c c * Nineth line: c Two floating point numbers (F12.8) Din and Dfin, the centrifugal c distortion constants in cm-1 for the initial and dissociative c electronic states. ( You may set either to 0.0 to ignore c centrifugal distortion.) Although some number is expected here, c centrifugal distortion is currently ignored by the program c for doublets and triplets. c c * Tenth line: c Two floating point numbers (F12.8) SOAin and SOAfin that give the c spin-orbit constants in cm-1 for the initial and dissociative c electronic states. (Set these to 0.0 if they are not appropriate c for the electronic state, e.g. for a singlet state). c c * Eleventh line: c One floating point number (F12.8) that gives Tev, the electronic c transition energy in cm-1 for the vibrational band desired. c You may have to look at the energy formulas in function Energy to c figure out exactly what is wanted here. c c * Twelth line: c Two floating point numbers (F12.8) that give startnu and range, c both in cm-1, which are the starting wavenumber for the simulation c and the range. c c * Thirteenth line: c Two integers (I5) ifin and iffin which tell the program which F c levels you would like simulated. ifin is for the initial state c and iffin is for the dissociative state. c Values are interpreted as follows: c 1 Do only F1 c 2 Do F1 and F2 c 3 Do F1 and F2 and F3 c 4 Do only F2 c 5 Do F2 and F3 c 6 Do only F3 c For a singlet state, choose a value of 1 c For a doublet sigma state, choose 2 (unless you resolve lambda doublets) c For a doublet pi state, note that in the case (a) limit c the F2 state is doublet pi 1/2 with J=N+S, while the F2 state c is doublet pi 3/2 with J=N-S c For a triplet sigma state, see c B. R. Lewis, S. T. Gibson, M. Emami, and J. H. Carver, c J. Quant. Spectrosc. Radiat. Transf. 40, 1 (1988). c J. B. Tatum and J. K. T. Watson, Can. J. Phys. 49, 2693 (1971). c c * Fourteenth line: c Two floating point numbers (F12.8) giving the spin-rotation splitting c constant Gamma in cm-1. This is usually small c and can often be neglected (i.e.set equal to zero). c The first number is for the initial electronic c state and the second is for the dissociative electronic state. c The number is ignored for singlet sigma states (just put in 0.) c c * Fifteenth line: c Two floating point numbers (F12.8) giving c the "little" lambda value in c for initial and dissociative state in cm-1 as c used in the energy equations in c B. R. Lewis, S. T. Gibson, M. Emami, and J. H. Carver, c J. Quant. Spectrosc. Radiat. Transf. 40, 1 (1988). c This number is ignored for singlet and doublet states, c but two numbers c are still expected to be read. (so enter 0. for such states) c Special note: If the first of these numbers is between 1.9 and 2.05 and c if the initial state is triplet sigma, the program assumes that the molecule c is O2 and applies the correct nuclear spin statistics. c c * Sixteenth line: c An integer, one of the following: c Each digit is interpreted separately to allow combinations c The ones digit (passed as icntrl to program): c 0 for normal operation c 1 for calculating the spectrum only. c Calculating the spectrum is no longer c much faster than calculating the spectrum and the angular c distribution, so this option is not particularly useful any longer. c 2 for outputing the angular distribtion at each point in the spectrum. c After each spectral element, the program writes the angular c angular distribution at that element to a file called angdist.dat c and then pauses. The operator can execute commands (like renaming c angdist.dat) and then hits return to do the next spectral element. c The tens digit (passed as inuc to program): c 0 for no nuclear spin statistics (gn=1 for all states) c 1 for ortho para in H2 in electronic ground state c 2-9 available for user modifications in function Pop to c allow users to put in whatever spin statistics are needed c See notes in function Pop for an explanation c The hundreds digit (passed as ihun to program) c do not use; reserved for future modifications c Summary: valid values are currently 0,1,2,and 10,11,12; c user modification can make available 20,21,22,30,31,32,etc. c c c End of Instructions on using Betaofnu A preprint of this work will soon be available: Hahkjoon Kim, Kristin S. Dooley, Simon W. North, G. E. Hall, and P. L. Houston, "Anisotropy of photofragment recoil as a function of dissociation lifetime, excitation frequency, rotational level and rotational constant," submitted (request preprint from plh2@cornell.edu) Download current Betaofnu. Program Instructions Revision Sheet Installation Instructions This work is supported by The Chemistry Division of the National Science Foundation "Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation."