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    On 14/02/2012 11:01 PM, James Starlight wrote:
    <blockquote
cite="mid:CAALQopxU8-ko33p88k6Ldb=OQyxXM3bam038RYM4QPYKaMfUTg@mail.gmail.com"
      type="cite">This also was solved by the some extra minimisation
      steps.<br>
      <br>
      <br>
      I've forced with another problem :D<br>
      <br>
      During npt equilibration my system have slightly expanded so my
      desired volume and density were perturbed.<br>
      <br>
      I've noticed the below options in npt wich could help me<br>
      <br>
      ref_p&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; = 1 1 &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br>
      compressibility = 4.5e-5&nbsp;&nbsp;&nbsp; <br>
      <br>
      &nbsp;i'm using this compressibility value&nbsp;&nbsp; because I'm modelling the
      lipid-like environment so I think that I must increase pressure.&nbsp;
      Could you remind me the dependence of pressure from density and
      volume for liquids ? :)<br>
    </blockquote>
    <br>
    Your forcefield, simulation cell contents and .mdp settings will
    determine the equilibrium density. Whether you need to do anything
    depends on whether you've made a statistically significant
    post-equilibration measurement of your average density. Haphazardly
    increasing the reference pressure for the coupling will reduce the
    volume, but now you are simulating at that pressure. See <a
      href="http://www.gromacs.org/Documentation/Terminology/Pressure">http://www.gromacs.org/Documentation/Terminology/Pressure</a>
    for background info.<br>
    <br>
    Mark<br>
    <br>
    <blockquote
cite="mid:CAALQopxU8-ko33p88k6Ldb=OQyxXM3bam038RYM4QPYKaMfUTg@mail.gmail.com"
      type="cite">
      <br>
      James<br>
      <br>
      <br>
      <br>
      <div class="gmail_quote">2012/2/14 James Starlight <span
          dir="ltr">&lt;<a moz-do-not-send="true"
            href="mailto:jmsstarlight@gmail.com">jmsstarlight@gmail.com</a>&gt;</span><br>
        <blockquote class="gmail_quote" style="margin:0 0 0
          .8ex;border-left:1px #ccc solid;padding-left:1ex">
          It seems that I've fixed that problem by reduce vdv radii for
          Cl during defining of my box<br>
          <br>
          Eventually I've obtained box with the desired density<br>
          &nbsp;than I've delete vdvradii.dat for my wor dir<br>
          <br>
          by when I've launched equilibration I've oibtained<br>
          <br>
          Fatal error:<br>
          Too many LINCS warnings (1598)<br>
          If you know what you are doing you can adjust the lincs
          warning threshold in your mdp file<br>
          <br>
          I've never seen this before<br>
          <br>
          I'm using 1.o cutoff for pme and 1.4 for vdv<br>
          my LINKS parameters are<br>
          <br>
          ; Bond parameters<br>
          continuation&nbsp;&nbsp;&nbsp; = no&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; ; first dynamics run<br>
          constraint_algorithm = lincs&nbsp;&nbsp;&nbsp; ; holonomic constraints <br>
          constraints&nbsp;&nbsp;&nbsp; = all-bonds&nbsp;&nbsp;&nbsp; ; all bonds (even heavy atom-H
          bonds) constrained<br>
          lincs_iter&nbsp;&nbsp;&nbsp; = 1&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; ; accuracy of LINCS<br>
          lincs_order&nbsp;&nbsp;&nbsp; = 4&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; ; also related to accuracy<br>
          <br>
          How I could solve it?<span class="HOEnZb"><font
              color="#888888"><br>
              <br>
              <br>
              James</font></span>
          <div class="HOEnZb">
            <div class="h5"><br>
              <br>
              <div class="gmail_quote">2012/2/14 James Starlight <span
                  dir="ltr">&lt;<a moz-do-not-send="true"
                    href="mailto:jmsstarlight@gmail.com" target="_blank">jmsstarlight@gmail.com</a>&gt;</span><br>
                <blockquote class="gmail_quote" style="margin:0 0 0
                  .8ex;border-left:1px #ccc solid;padding-left:1ex">Mark,<br>
                  <br>
                  I've checked only density value<br>
                  <br>
                  with 500 molecules Ccl4 I have&nbsp; density that is
                  twisely less that I need ( in accordance to the
                  literature ). Also I've checked my box visually and
                  found that the box is not properly tightly packed so I
                  dont know why genbox didnt add some extra mollecules
                  :(<br>
                  <br>
                  In other words I wounder to know if&nbsp; there is any way
                  to add some extra molecules to the pre defined box to
                  make my system more tighly packed&nbsp; ( to short distance
                  between existing molecules and place new ones in the
                  new space ) ?<span><font color="#888888"><br>
                      <br>
                      James</font></span>
                  <div>
                    <div><br>
                      <br>
                      <div class="gmail_quote">2012/2/14 Mark Abraham <span
                          dir="ltr">&lt;<a moz-do-not-send="true"
                            href="mailto:Mark.Abraham@anu.edu.au"
                            target="_blank">Mark.Abraham@anu.edu.au</a>&gt;</span><br>
                        <blockquote class="gmail_quote" style="margin:0
                          0 0 .8ex;border-left:1px #ccc
                          solid;padding-left:1ex">
                          <div>On 14/02/2012 4:57 PM, James Starlight
                            wrote:<br>
                            <blockquote class="gmail_quote"
                              style="margin:0 0 0 .8ex;border-left:1px
                              #ccc solid;padding-left:1ex">
                              Justin,<br>
                              <br>
                              Firstly I've created the box of desired
                              size with only 500 molecules ( I need
                              1000)<br>
                              <br>
                              Than I've tried to add extra 200 molecules
                              by means of Genbox<br>
                              <br>
                              genbox -cp super_box.gro -ci Ccl4.gro
                              -nmol 200 -o new_solv.gro<br>
                              <br>
                              but no molecules have been added<br>
                              Added 0 molecules (out of 200 requested)
                              of Cl4<br>
                            </blockquote>
                            <br>
                          </div>
                          ... then there are no gaps large enough to
                          insert your molecules. Either make gaps, or
                          check out genbox -h for advice on defining the
                          radii.
                          <div><br>
                            <br>
                            <blockquote class="gmail_quote"
                              style="margin:0 0 0 .8ex;border-left:1px
                              #ccc solid;padding-left:1ex">
                              <br>
                              also I've tried<br>
                              <br>
                              genbox -cp super_box.gro -cp Ccl4.gro
                              -nmol 200 -o new_solv.gro<br>
                            </blockquote>
                            <br>
                          </div>
                          Two -cp options is not what you want, and
                          -nmol probably only works with -ci.
                          <div><br>
                            <br>
                            <blockquote class="gmail_quote"
                              style="margin:0 0 0 .8ex;border-left:1px
                              #ccc solid;padding-left:1ex">
                              <br>
                              but system were crashed with message<br>
                              <br>
                              Reading solute configuration<br>
                              God Rules Over Mankind, Animals, Cosmos
                              and Such<br>
                              Containing 2500 atoms in 500 residues<br>
                              Initialising van der waals distances...<br>
                              <br>
                              WARNING: masses and atomic (Van der Waals)
                              radii will be determined<br>
                              &nbsp; &nbsp; &nbsp; &nbsp; based on residue and atom names.
                              These numbers can deviate<br>
                              &nbsp; &nbsp; &nbsp; &nbsp; from the correct mass and radius
                              of the atom type.<br>
                              <br>
                              Reading solvent configuration<br>
                              "God Rules Over Mankind, Animals, Cosmos
                              and Such"<br>
                              solvent configuration contains 5 atoms in
                              1 residues<br>
                              <br>
                              <br>
                              Is there any ways to add extra mollecules
                              to the pre defined box ?<br>
                            </blockquote>
                            <br>
                          </div>
                          Yes - but there has to be room for them.<span><font
                              color="#888888"><br>
                              <br>
                              Mark</font></span>
                          <div>
                            <div><br>
                              -- <br>
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