<div dir="ltr">Hi Izzy,<div><br></div><div>Yes that is the typical way to get around that error. You could try larger values of the cfl, 0.1 is usually a good starting place and would be ~10x faster than the 0.01 value you're using.<br><br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div dir="ltr" style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">*************************************************************************</div><div dir="ltr" style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">Adam Reyes<div><img src="https://flash.rochester.edu/site/common/images/email_signature/FLASH.jpg"><br></div><div>Code Group Leader, Flash Center for Computational Science <span> </span><br></div><div>Research Scientist, Dept. of Physics and Astronomy</div><div>University of Rochester</div><div>River Campus: Bausch and Lomb Hall, 369 <span> </span><br></div><div>500 Wilson Blvd. PO Box 270171, Rochester, NY 14627</div><div dir="ltr">Email<span> </span><a href="mailto:adam.reyes@rochester.edu" target="_blank">adam.reyes@rochester.edu</a></div><div>Web<span> </span><a href="https://flash.rochester.edu/" target="_blank">https://flash.rochester.edu</a><br></div><div> (he / him / his)</div><div><img src="https://flash.rochester.edu/site/common/images/email_signature/FLASH-pride-sml.png"><br></div>*************************************************************************</div></div></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Aug 9, 2023 at 7:55 PM Rodger, Izzy <<a href="mailto:rodger1@llnl.gov">rodger1@llnl.gov</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">



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Good morning!</div>
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I'm trying to run the LasSlab example using equation of state tables in the sesame format, however an error message that I'm encountering often is:</div>
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[hy_uhd_eigenParameters-A]: Zero or imaginary sound speed has obtained! Please <u></u>
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<span> </span>try other (more diffusive) slope limiter, flux, order, cfl, etc.</p>
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The position of this error in the simulation seems to be at different points along the target-chamber boundary.</div>
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A forum post from 2019 recommended lowering the cfl, and when I did this (lowered it from 0.8 to 0.01) I was able to run the simulation and receive a reasonable output - but the runtime is very long. I do not receive the error when I use the pre-packaged ionmix4
 file for aluminium, and it runs in a much better time. Perhaps it is a problem with my EOS table?</div>
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Does anybody have any ideas for what else I could do to try and resolve this issue without sacrificing simulation runtime?</div>
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Kind regards,</div>
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Izzy</div>
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