Sometimes users ask us to implement a feature like plotting multiple spectra (from different files) in a single graph. We do not plan to implement such features, because:
1) This will require a reconstruction of the user interface, and old users will have to learn how to use Chemcraft again;
2) For building graphs of any type, powerful software packages already exist – Excel, Origin, etc. We do not want to compete with them. But Chemcraft allows one to export any graph, spectrum, diagram in text format, copying its data to Excel via Clipboard. So, multiple spectra in one picture can be easily obtained as follows: you should open several output files in a row, copy the data with spectra to Excel and then combine these spectra in Excel. Note that the broadened spectrum (Doppler, Lorentzian broadening of bands) can be exported too.
See, for example, this graph built in Chemcraft:
This is a Gaussian09 Born-Oppenheimer Molecular Dynamics (BOMD) computation, and the graph shows the distance between atoms C1 and H1 versus time in femtoseconds. There seems to be a problem, or a bug, with visualization of such files – Chemcraft reads the first 3 points with zero time. We found the format of the output file quite difficult. Maybe this problem will be fixed in future, but we are not even sure that this is necessary: if you need to plot a good graph “Distance vs Time”, click on the “Copy” button, insert the data into Excel and manually delete the invalid lines. Of course you should check your graph against the output file – if you work with BOMD computations, you should understand them well enough.
We always give our users the possibility to verify the data visualization in Chemcraft – for example, when you visualize the molecular orbitals, you can click the “Check orbitals” button to check whether Chemcraft extracted all orbitals correctly. When we implement visualization of MOS from output files of new software, it is sometimes difficult to thoroughly verify whether the MOS are visualized correctly (probably free software is characterized with such problems to a greater extent). And don’t forget to check the data shown by Chemcraft using the Source mode.