• SVIEW_L = viewer of the spectrum, based on program SVIEW
• ASCP_L = viewer of predictions, based on program ASCP

        which are integrated with several other programs. The package also comprises of the utility program AC, which allows generation of dataset distribution plots that allow rapid overview of large spectroscopic datasets.

       ASCP_L is normally used as the active program, and the display of SVIEW_L is locked to it. Predictions of spectroscopic species of relevance to the current spectrum can be loaded into the program and displayed with various options for distinguishing between the various species. A special highlighting option by 'cloning' the current line allows highlighting of a transition sequence of interest. Frequency regions around successive predictions in this sequence can then easily be inspected in turn, and if there are suitable lines in the spectrum those can be measured. The frequency determined by SVIEW_L and quantum numbers from ASCP_L can be added to a specified datafile for the fitting program. When deviations from predictions are not too large then the analysis process involves only two keystrokes per line. Predictions and data for fitting can be in the standard of either SPFIT/SPCAT or ASFIT/ASROT packages.

        An alternative mode of operation is to draw a Loomis-Wood type plot of strips of the experimental spectrum centred on successive highlighted lines. This display in the basic mode actually uses stick representation of peakfinder results instead of the actual spectrum, which enables very fast operation. This mode is especially suitable for earlier stages of assignment. Measurements and addition of data to the fitting file can be made in a very economic way in both the main display mode and in the LW mode. requiring only two-three keystrokes per spectral line.

• snapaabs - standard alignment of the two programs as launched using the configuration files below. The predictions consist of four data files, which are a mixture of .ASR and .CAT files, and are for ground states of two different isomers and some excited vibrational states of diethyl ether. Different species are drawn in different colours and a transition sequence in one of these has been highlighted in white.
• snapai - the summary of information on the loaded prediction data files. Eleven different files, consisting of a mix of .ASR and .CAT files have been read and their transitons merged and sorted for plotting.
• The primary help system is as contained in the present AABS_HELP.CHM file, but it is also possible to display online help screens with Ctrl H. For the ASCP_L basic display mode these are: snapah1 - the main online help screen, snapah2 - the second help screen summarising the ASCP_L commands that are specific to linked operation with SVIEW_L, and snapah3 - the third help screen summarising the files that can be used by ASCP_L

         In addition to the basic mode the Loomis-Wood type mode offers extended display possibilities. The LW strips can be drawn as a simple stick representation of the spectrum, as open and filled triangle approximations to the spectrum and can also be from the actual spectrum. Several alternative colour schemes and output leading to PostScript/PDF diagrams are available.

• snaplw - the preferred open triangle mode of the LW screen, which provides an optimum between clarity and speed of operation and has been adapted from the excellent Loomis-Wood program written in the Winnewisser group in Giessen. This plot plot obtained on pressing the F5 key while in the normal display, after having marked a transition sequence in the standard mode, as in the snapshot snapaabs above. The spectral strips can be easily scrolled in four directions, a movable cursor is available to select desired lines, and indication of assigned lines can be toggled on and off.
• snaplwst, snaplwft - stick type and filled triangle versions of the LW display, which are toggled through by pressing the p key. Useful for more broadband, and more close in work, respectively.
• snaplws - Loomis-Wood type plot using strips of the actual spectra, obtained by pressing the [ key in the LW display mode.
• scheme1, scheme2, scheme3 - some of the different colour schemes for the LW display, which can selected with the he C key in the LW display mode.
• snaplwt.pdf - result from output for the gle program, which is automatically generated for the Loomis-Wood display as above. Gle can then be used to compile the generated files into PostScript and PDF diagrams. Such diagram can also be generated in portrait orientation.
• snaplws.pdf - PDF for a LW plot based on an actual spectrum
• snaplwh - the help screen in the Loomis-Wood type plot

• Create a directory called C:\ROT on your computer and place in it the five files: 

• Place shortcuts to SVIEW_L and ASCP_L on the desktop. And this is all!

• Actually this is not all for the more recent versions of Windows in which you might get the message "Msvcr71.DLL cannot be found" when you try to launch either of the two programs. If that is the case you also need the file MSVCR71.DLL, which is best placed in the same directory as the programs, namely C:\ROT.

Control Panel->System->Advanced->Environment Variables-> PATH

and to append ;c:\rot to the value of that variable. Another way involves locating the file AUTOEXEC.NT, normally in C:\WINDOWS\SYSTEM32 and adding to it the line path=c:\rot if there was no previous such line in this file, and if there is one then append to it  ;c:\rot.

        You might want to download a complete sample project, and follow the associated mini-tutorial to check out some features of the package without the need for setting up a project from scratch.

• Create a directory which is to contain all work associated with analysis of a given spectrum.

• Copy your broadband spectrum to this directory - it is recommended that the spectrum be in the compact binary mode used by SVIEW_L. This can easily be generated since SVIEW_L can read a spectrum as a two column ASCII file of point frequencies and intensities (preferably, but not necessarily, equally spaced in frequency). Binary file is then generated with the M option.

• Generate peakfinder output for this spectrum if Loomis-Wood type plots are to be used for assignment. This is to be done by using the automatic peakfinder of SVIEW_L, which is invoked by specifying a negative value for the 0 option.

• Make sure you have either SPFIT/SPCAT or ASFIT/ASROT running on your computer, the relevant executables can also be placed in directory C:\ROT

• It is highly recommended that you have a text editor that is able to sense that the contents of an opened file has changed and it can then refresh it. The standard Notepad editor is not able to do this but, for example, the PSPAD editor can.

• Edit a suitable version of the SVIEW_L.INP file

• Edit a suitable version of the MOLNAM.INP file, which declares the names of prediction files to be displayed by ASCP_L.

• When working with a segmented spectrum it is, optionally, possible to use a file called LIST to specify the frequency segments for which there is data. This file can either be created using SLIST (if the component spectra are available) or by reediting this LIST example - only the frequency entries are of relevance.

• From your favourite file manager drag and drop the spectral file onto the SVIEW_L icon on the desktop, then press ENTER

• Drag and drop the MOLNAM.INP file onto the ASCP_L icon on the desktop. Press 2 ENTER for batch input, and then just ENTER as a data file name.

• In the text editor open the data files associated with fitting the current spectroscopic species of interest as declared in SVIEW_L.INP. These might be either .LIN, .PAR, .FIT files for SPFIT, or .ASF, .RES files for ASFIT

• Open a command prompt window, with the current directory set to the work directory for the current problem

• The two viewing programs should have opened as two adjacent strips. Almost all operations are carried out from within ASCP_L, which controls the display of SVIEW_L as necessary. There are, however, two tuning tasks for dealing with the spectrum that it might be necessary to perform in SVIEW_L. One is setting the optimum width of the fitting window for determining line frequencies - expand a line profile with A/S keys and optimise using the O and 0 options. Another task is Y-axis scaling of the spectrum - use W/Z and 2/3 keys.

• Click (or use ALT TAB) to make ASCP_L the active window - this should be the lower of the two strips. Note that there is minimal mousing around - almost all commands are issued from the keyboard, which is a much faster device and allows increased efficiency. It pays to study and learn the main keys for controlling the programs and two summary charts ASCP_L_KEYS.PDF and SVIEW_L_KEYS.PDF have been prepared to print and keep handy. Note that the navigation commands for the two programs are identical.

• Move to the stick corresponding to a line from a line sequence of interest and highlight this sequence with t. It might actually be easier to just move to any line predicted for this spectroscopic species, use T to preselect a range of lines, and then find the desired type of line with left/right arrows. Subsequently t will highlight the sequence precisely.

• Move along the lines in the highlighted sequence with left/right arrows and make measurements as necessary, mainly with F1 or F2. If a line in the spectrum is significantly off the cursor position you can move closer to it with 2/3 keys of ASCP_L and then measure.

• You might want to check on the progress of accumulation of measurements in the fitting data file by moving to the text editor window. The data file is not locked by the AABS programs so that lines can be rearranged/tidied, the file saved, and further data will be appended to the modified file.

• Go to the command line window and carry out fitting and prediction in your favoured way. It is recommended to browse through the results file from the fit prior to embarking on predictions. If working with SPFIT you might find it useful to reformat the .FIT file with program PIFORM, which improves readability and allows annotations on the data file. The fitting/prediction is not automated on purpose. It is hoped that in this way the user can spot any problems earlier and will take suitable corrective action, before it is too late.

• Once new predictions are ready press ESC in ASCP_L, which updates predictions, as well as markers of lines already measured. To switch to a new spectroscopic species place the name of the new file for the fitting program in SVIEW_L.INP and update both SVIEW_L and ASCP_L by pressing ESC.

• In more difficult cases launch the Loomis-Wood display by setting the cursor on a highlighted line and pressing F5. Use the help screen of this display for information. The steps above can be carried out as many times as necessary - it is not necessary to close the two display programs at any stage.