<div style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial"><p data-start="97" data-end="114" class="">Dear Flash Users,</p><p data-start="116" data-end="364" class="">Hello! I am currently modifying <em data-start="148" data-end="159">LasersLab</em> and have encountered an issue related to mass fractions. My simulation involves two materials, <code data-start="255" data-end="266">CHAM_SPEC</code> and <code data-start="271" data-end="282">TARG_SPEC</code>, with EOS tables <code data-start="300" data-end="318">"he-imx-005.cn4"</code> and <code data-start="323" data-end="350">"polystyrene-imx-008.cn4"</code> respectively.</p><p data-start="366" data-end="478" class="">To ensure a smooth variation of volume fractions across the interface, I made the following changes in the code <font face="monospace">"Simulation_initBlock.F90"</font>:</p><pre class="overflow-visible!" data-start="480" data-end="951"><div class="contain-inline-size rounded-md border-[0.5px] border-token-border-medium relative bg-token-sidebar-surface-primary"><div class="overflow-y-auto p-4" dir="ltr"><code class="whitespace-pre! language-fortran">xshift = -sim_initA * cos(2*pi*ycent(j)/sim_lambda)
fracCham = erfc( (xcent(i)-xshift)*slopeCoe ) / 2
fracTarg = 1.0 - fracCham
rho = sim_rhoCham * fracCham + sim_rhoTarg * fracTarg
MfracCham = sim_rhoCham * fracCham / rho

call Grid_putPointData(blockId, CENTER, DENS_VAR, EXTERIOR, axis, rho)
call Grid_putPointData(blockID, CENTER, CHAM_SPEC, EXTERIOR, axis, MfracCham)
call Grid_putPointData(blockID, CENTER, TARG_SPEC, EXTERIOR, axis, 1.0 - MfracCham)
</code></div></div></pre><p data-start="953" data-end="1027" class="">However, during execution, the simulation encountered the following error:</p><pre class="overflow-visible!" data-start="1029" data-end="1701"><div class="contain-inline-size rounded-md border-[0.5px] border-token-border-medium relative bg-token-sidebar-surface-primary"><div class="overflow-y-auto p-4" dir="ltr"><code class="whitespace-pre!">Newton<span class="hljs-operator">-</span>Raphson failed <span class="hljs-keyword">in</span> multitemp<span class="hljs-punctuation">,</span> multitype Eos.F90
MODE_DENS_EI_ION
INPUTS<span class="hljs-operator">:</span>
mass density                 <span class="hljs-operator">=</span>                      <span class="hljs-literal">NaN</span>
ion specific internal energy <span class="hljs-operator">=</span>                      <span class="hljs-literal">NaN</span>

CURRENT ITERATION<span class="hljs-operator">:</span>
ion specific internal energy <span class="hljs-operator">=</span>                      <span class="hljs-literal">NaN</span>
ion temperature              <span class="hljs-operator">=</span>                      <span class="hljs-literal">NaN</span>
mass fractions<span class="hljs-operator">:</span>
  cham   <span class="hljs-number">1.000000000000000E+00</span>
  targ   <span class="hljs-number">1.000000000000000E+00</span>

 too many iterations<span class="hljs-punctuation">,</span> reached          <span class="hljs-number">50</span>

  k    <span class="hljs-operator">=</span>            <span class="hljs-number">1</span>           <span class="hljs-number">1</span>           <span class="hljs-number">1</span>
  temp <span class="hljs-operator">=</span>                        <span class="hljs-literal">NaN</span>
  dens <span class="hljs-operator">=</span>                        <span class="hljs-literal">NaN</span>
  pres <span class="hljs-operator">=</span>                        <span class="hljs-literal">NaN</span>
 DRIVER_ABORT<span class="hljs-operator">:</span> <span class="hljs-punctuation">[</span>Eos<span class="hljs-punctuation">]</span> Error<span class="hljs-operator">:</span> too many iterations <span class="hljs-keyword">in</span> Newton<span class="hljs-operator">-</span>Raphson
</code></div></div></pre><p data-start="1703" data-end="2002" class="">What’s puzzling is that the mass fractions for both <code data-start="1755" data-end="1761">cham</code> and <code data-start="1766" data-end="1772">targ</code> appear to be 1.0 simultaneously. I used VisIt to examine the pseudocolor plots of <code data-start="1855" data-end="1861">cham</code> and <code data-start="1866" data-end="1872">targ</code>, and they show a smooth transition at the interface as expected. I also verified that <code data-start="1959" data-end="1972">cham + targ</code> equals 1.0 across the domain.</p><p data-start="2004" data-end="2145" class="">I’m trying to understand what might be going wrong and how I should modify the code to resolve this. Any advice would be greatly appreciated.</p><p>







</p><p data-start="2147" data-end="2177" class="">Best regards,<br data-start="2160" data-end="2163">
Xiangchen Feng</p></div><br>