Example
<?xml version="1.0"?>
<!DOCTYPE parratt SYSTEM "parratt.dtd">
<parratt type="parratt" do_fit="no">
<output>
<reflectivity>reflectivity.txt</reflectivity>
<profile>profile.txt</profile>
<q_min> 0.000</q_min>
<q_max> 0.160</q_max>
<num_q>300</num_q>
<num_z>200</num_z>
</output>
<model>
<bulk>
<name>ambient</name>
<thik fix="1">n/a</thik>
<sigz fix="1">n/a</sigz>
<rsld fix="1"> 0.000</rsld>
</bulk>
<layer>
<name>PS</name>
<thik fix="1">1000.000</thik>
<sigz fix="1">40.0</sigz>
<rsld fix="1"> 9.13</rsld>
</layer>
<layer>
<name>Ge</name>
<thik fix="1">19.700</thik>
<sigz fix="1"> 5.000</sigz>
<rsld fix="1"> 22.58</rsld>
<isld fix="1"> 0.000</isld>
</layer>
<substrate>
<name>glass</name>
<thik fix="1">n/a</thik>
<sigz fix="1"> 1.700</sigz>
<rsld fix="1"> 22.58</rsld>
<isld fix="1"> 0.000</isld>
</substrate>
<coverg fix="1"> 1.000</coverg>
<backgd fix="1"> 0.000</backgd>
<resoln type="dq/q"> 0.040</resoln>
</model>
</parratt>